How can these forelimbs explain how life changes over time?

The correct answer would be divergent evolution showing by homologous organs.

Explanation:

In the illustration human arm, the flipper of the dolphin, wings of bat and forearm of frog are shown. All  these four forelimbs have a different function, however, these forelimbs are having the same underlying anatomy.

The organs having basic structure and origin, but different functions are known as homologous organs. These organs point towards the same ancestor from these organisms evolved. They show a case of divergent evolution.

When related species become less similar in order to adapt and survive in different conditions, evolution is called divergent evolution.

Thus, these forelimbs provide evidence for divergent evolution.

the answer is d.) homologous; have mammary glands