Question

Which word is the simple subject of the sentence?

Whales are mammals that live in the ocean.

A.
mammals

B.
ocean

C.
whales

D.
live

Answer 1

C. Whales. Because normally it is the first word and even though mammals would be considered a subject, it isn't the main subject. 

Hope this helps!! :)

Answer 2

A is your answer i believe