In what way was Siddhartha Gautama an example of a bodhisattva?

He was a prince who ruled wisely and well.

He was responsible for building many stone pillars that express Buddhist beliefs.

He gained enlightenment and tried to help others out of compassion.

He was a member of the priestly caste and worshipped the gods.

The correct answer is:

He gained enlightenment and tried to help others out of compassion.