Whales and hippos are thought to have evolved from a common ancestor around 54 million years ago. which of the following is also true about these species? a. whales and hippos are physically identical. b. whales and hippos share many genetic similarities. c. whales and hippos can interbreed to produce offspring. d. whales and hippos have not changed in the past 54 million years.

I'd say B, the first is wrong because they look nothing alike third one is wrong because you just don't see that happening (obviously) choose B it's in the DNA if they according to D evolved from the same ancestor then they share genetics

In the animal kingdom there is a lot of diversity...

First:
There are carnivores, herbivores and omnivores. Carnivores eat strictly meat. Herbivores eat vegetation and plants. Omnivores are like you and I, we eat anything, meat, vegetation, etc. 

Second: 
There are several main classes, the Land Animals, the Sea Animals and the Air Animals. 
Land: Anything such as horses, deer, cats, camels, lizards, bears, foxes, moles, mice, dogs, tigers, lions, zebra, cows, goats, pigs, ocelots, monkeys, etc. 
Sea: Sharks, fish, octopus, dolphins, whales, sea horses, sea urchins, eels, sturgeon, angel fish, etc. 
Air: Hawks, eagles, vultures, toucans, parrots, crows, ravens, blackbirds, blue jays, chickadees, woodpeckers, swallows, etc. 

Third: 
There are classes such as feathered (birds), scaled (reptiles), furred and such.
Feathered: Chickens, eagles, toucans, turkeys, grouse, ravens, crows, etc.
Scaled: Lizards, snakes, sharks, fish, etc.
Furred: (Domestic) Horses, cows, dogs, cats, monkeys, etc. (Non domestic) Lions, tigers, bears, deer, elk, moose, etc.