Here's a problem to solve: Joanne's science teacher cautioned the class to be skeptical when learning about new scientific discoveries. Why is it important to be skeptical about new discoveries in science?

Among the 4 following options, which is the correct answer?

- A: because many scientific discoveries are not based on facts
 
- B: because most scientific discoveries have no scientific value
 
- C: because most scientists make errors when formulating scientific discoveries
 
- D: because all scientific discoveries must be examined critically before they can be accepted
 