The correct answer is are. This question tests your understanding of subject-verb agreement when using correlative conjunctions like "either...or." When "either...or" connects two subjects, the verb must agree with the subject that is closer to it. This is known as the rule of proximity or the rule of the nearest subject. The verb takes its number from the noun or pronoun immediately preceding it.
In the sentence "Either Ahmed or his friends __________ coming today," the two subjects are "Ahmed" (singular) and "his friends" (plural). The subject closer to the blank (and thus the verb) is "his friends," which is a plural noun. Therefore, the verb must also be plural to agree with "his friends."
- Is: This is a singular verb and would be incorrect because the closer subject "his friends" is plural.
- Was: This is a singular past tense verb and is incorrect for the same reason as "is," and also because the sentence implies a present action.
- Has: This is a singular verb (or used with singular subjects in present perfect tense) and is incorrect because the closer subject "his friends" is plural.
By applying the rule of proximity for "either...or" constructions, we correctly choose the plural verb "are" to agree with "his friends."