The tail grows and the gills disappear. The gills develop and the front legs appear. The rear legs grow and the lungs disappear. The lungs develop and the tail becomes shorter.
I gave my students this multiple choice question: In the life cycle of a frog, which of the following best describes what happens after the tadpole stage?

Only one answer is correct among these 4 choices:
- The tail grows and the gills disappear.
- The gills develop and the front legs appear.
- The rear legs grow and the lungs disappear.
- The lungs develop and the tail becomes shorter.

Could you tell me which one is correct?

The lungs develop and the tail becomes shorter.