Read the following sentence. Mark yelled, "Please help Mike and I move this shipment. It's heavy!"

Which of the following choices correctly identifies the pronoun error in the above sentence?

A.
An object pronoun is being used where an subject pronoun is needed.
B.
A pronoun disagrees in number with its antecedent.
C.
A subject pronoun is being used where an object pronoun is needed.
D.
A pronoun in the sentence has an unclear antecedent.