by tossing a ball in the air by shaking the ends of a rope by throwing a pebble into a pool of water by pulling on a coiled spring toy
I gave my students this multiple choice question: Students are learning about different types of waves. Which is the least likely way for the students to generate a wave?

Only one answer is correct among these 4 choices:
- by tossing a ball in the air
- by shaking the ends of a rope
- by throwing a pebble into a pool of water
- by pulling on a coiled spring toy

Could you tell me which one is correct?

by tossing a ball in the air