Here's a problem to solve: Comparing the skeletons of which of the following fish would best show the evolution of a fish species?

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

- A: a male fish and a female fish that could produce offspring
 
- B: the same fish just before it received a cut and after it healed
 
- C: a fish that lived recently and a fish that lived a long time ago
 
- D: the same fish just after it hatched and when it was full-grown
 