Which rule best explains why the verb in the following sentence is correct?

The owner or the business managers need to prepare the annual budget.

A.This sentence has a mixed compound subject connected by or, so the verb agrees with the first singular subject.
B .A plural indefinite pronoun comes before the compound subject, so a plural verb is used.
C.Both parts of the compound subject are plural, so a plural verb is used.
D.This sentence has a mixed compound subject connected by or, so the verb agrees with the plural subject that is closer.