Answer:
A, sharks use gills, most sharks have 5, like the great white. Whales are mammals, they breath through their blow holes
Step-by-step explanation:
I am a shark expert. I've studied them for over ten years (since I was 4)
Fun fact: Did you know the Great white shark is warm blooded? most sharks are cold blooded and like warm waters, but the great white is commonly found in colder waters!