This sentence contains an error in the subject-verb concordance. The theme of the sentence is “reports”, so the verb “a” must be changed to the plural “have” to be consistent with the plural theme “relations”. Rule 5a. Sometimes the subject is separated from the verb by words like with, as well as, next to it, not, etc. These words and phrases are not part of the topic. Ignore them and use a singular if the subject is singular. The simple subject of the sentence is “everyone”, so the predicate should be singular and not plural. In this sentence, “each of the students” is the subject, so we need a singular predicate. The only answer that contains a singular predicate for the subject “Each of the students” is “Each of the students was sick last week, so the professor canceled the course.” The verb “are” corresponds to a plural meeting, but the subject of this sentence is the singular “couple”. If you change “are” to “is”, the error in the sentence is corrected.