The correct answer is 3. Neither he nor his parents think he’ll have time to do the work for both courses, and both is offered at the same time.
Explanation:
The pronoun-verb agreement refers to the grammatical connection established between the pronoun or subject and the verb in a sentence, according to grammar the verb changes depending on the noun, especially if the noun is plural (for example they,we) or singular (for example she, he). On the other hand, indefinite pronouns are pronouns that refer to non-specific nouns or subjects but have the same grammatical function as a noun, these include words such as someone, few, all, somebody or both. Considering this, if a sentence includes the word "both" it expresses plural and therefore the verb should be modified according to it, this means "both is offered" in sentence 3 is incorrect as the noun "both" is plural and the verb "is" refers to singular, therefore there is no agreement between the verb and the noun, instead this sentence should be "both are offered" with a noun and verb in plural.
