The answer is:
D) The man, in the next apartment, as well as the people across the hall, have lived in the building since 1960.
Subject-verb agreement means that the subject and the verb must possess the same number. Thus, when the subject is singular, the verb must be singular; and when the subject is plural, the verb must be plural too.
In sentence D, there is no subject-verb agreement because the subject is singular (the man) and the auxiliary verb is plural (have). The correct sentence is:
The <u>man</u>, in the next apartment, as well as the people across the hall, <u>has lived</u> in the building since 1960.
