There ___ been more than a dozen incidents of spontaneous human combustion in my classroom this year.
C. either of the above
Answer and Explanation
This is a question of subject/verb agreement. Has is a singular verb; have is the plural form. Verbs should agree in number with their subjects.
So the question is, what is the subject of the verb in this sentence? And that's where it gets a little tricky.
The sentence is inverted, meaning the subject comes after the verb instead of the other way around. Sentences that begin with here and there are often inverted this way. And if you aren't careful, it's easy to misidentify the subject. Is it more, dozen, incidents, combustion, classroom?
Well, simply. It's incidents. More than a dozen is an adjective phrase that modifies incidents (How many incidents? More than a dozen.) Combustion is the object of the prepositional phrase of human combustion and classroom is the object of the prepositional phrase in my classroom.
And since incidents is plural, you need the plural verb have.
B is the right answer.