The correct answer is b. I used my notes from art class so it should be correct
Answer:
One theory had been that hippos were related to pigs. Yet mounting evidence suggested they are closer to whales. A new study concludes that a four-footed semi-aquatic mammal that thrived for some 40 million years was a common ancestor to both whales and hippos.
Explanation:
Starfish has a endoskeleton
a coral has a exoskeleton
sponge has neither
