Which sentence contains an intransitive verb?

AIan sharpened his hockey skates.
BCarla skates before school in the morning.
COur hockey team won the league championship.
DJenna chose Hector as her skating partner.

Verified Answer :

I believe. Its A ask someone else just to make sure

An intransitive verb doesn't require a direct object. A cannot be correct because, Ian sharpened what? His hockey skates. So that is the direct object, therefore the verb is transitive. C and D are the same case.
The correct answer is B, because the verb is intransitive as it doesn't need an object. You cannot answer - Carla skates what? No, it is just Carla skates.