Choose the correct one.
Choose the correct one.
A: A series of lectures was delivered
B: A series of lectures were delivered
C: A series of lecture was delivered
D: None of these
Series is a singular collective noun when it takes the article a. Therefore the verb must be singular. Lectures stays plural because the series contains many talks. Option B mismatches the singular head with a plural verb. Option C breaks noun form agreement. Thus was delivered is the correct verb.