Here's a short story:

The annelids are bilaterally symmetrical, triploblastic, coelomate, invertebrate organisms. They also have parapodia for locomotion. Most textbooks still use the traditional division into polychaetes (almost all marine), oligochaetes (which include earthworms) and leech-like species. Cladistic research since 1997 has radically changed this scheme, viewing leeches as a sub-group of oligochaetes and oligochaetes as a sub-group of polychaetes. In addition, the Pogonophora, Echiura and Sipuncula, previously regarded as separate phyla, are now regarded as sub-groups of polychaetes. Annelids are considered members of the Lophotrochozoa, a "super-phylum" of protostomes that also includes molluscs, brachiopods, flatworms and nemerteans. 

The basic annelid form consists of multiple segments. Each segment has the same sets of organs and, in most polychaetes, has a pair of parapodia that many species use for locomotion. Septa separate the segments of many species, but are poorly defined or absent in others, and Echiura and Sipuncula show no obvious signs of segmentation. In species with well-developed septa, the blood circulates entirely within blood vessels, and the vessels in segments near the front ends of these species are often built up with muscles that act as hearts. The septa of such species also enable them to change the shapes of individual segments, which facilitates movement by peristalsis ("ripples" that pass along the body) or by undulations that improve the effectiveness of the parapodia. In species with incomplete septa or none, the blood circulates through the main body cavity without any kind of pump, and there is a wide range of locomotory techniques – some burrowing species turn their pharynges inside out to drag themselves through the sediment. (End of story)

Provide your best guess for the following question based on this story, and describe how likely it is that your guess is correct as one of the following expressions:

Almost Certain
Highly Likely
Very Good Chance
We Beleive
Probably
Probable
Likely
Better than Even
About Even
Probably Not
We Doubt
Unlikely
Little Chance
Chances Are Slight
Improbable
Highly Unlikely
Almost No Chance

Give ONLY the guess and your confidence, no other words or explanation. For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>
Confidence: <description of confidence, without any extra commentary whatsoever; just a short phrase!>

Here are a few examples of questions and answers:

Question: What research has changed something substantially?
Guess: Cladistic research
Confidence: <appropriate level of confidence in this guess>

Question: What has it changed?
Guess: the scheme
Confidence: <appropriate level of confidence in this guess>

Question: Since what year?
Guess: 1997
Confidence: <appropriate level of confidence in this guess>

Question: What group are Annelids associated with?
Guess: Lophotrochozoa
Confidence: <appropriate level of confidence in this guess>

Question: Is that a type of protosome?
Guess: Yes
Confidence: <appropriate level of confidence in this guess>

Question: What kind?
Guess: "super-phylum"
Confidence: <appropriate level of confidence in this guess>

Question: Are annelids described as not being the same on each side?
Guess: No
Confidence: <appropriate level of confidence in this guess>

Question: What modifier is used to describe their symmetry?
Guess: Bilaterally
Confidence: <appropriate level of confidence in this guess>

Question: What group are leeches a sub-category of ?
Guess: Oligochaetes
Confidence: <appropriate level of confidence in this guess>

Question: What are they a sub-group of ?
Guess: Polychaetes
Confidence: <appropriate level of confidence in this guess>

Question: Do most books still classify these creatures into five categories?
Guess: No
Confidence: <appropriate level of confidence in this guess>

Question: How many then?
Guess: Three
Confidence: <appropriate level of confidence in this guess>

Question: What is used for motion in the creatures?
Guess: Parapodia
Confidence: <appropriate level of confidence in this guess>

Question: A single one?
Guess: No
Confidence: <appropriate level of confidence in this guess>

Now answer the following question in the same format.

Question: What is responsible for the separation of segments?

Septa