Luis goes to the Museum of Natural History and sees a display of bones from a dolphin's flipper and a cat's leg. They are very different, but the display shows that their bones have homologous structures in their limbs. What can you infer about these two organisms from their homologous structures?

A. They evolved at the same time.
B. They evolved rapidly.
C. They related and share a common ancestor.
D. They live in similar environmental conditions.