The correct answer is: C. Our neighbor was bitten by their dog yesterday.
The verb “to bite” is a transitive verb, which means that it requires a direct object. In this case, the direct object is “our neighbor.” The past tense of “to bite” is “bit,” and the past participle is “bitten.” The sentence “Our neighbor bit their dog yesterday” is incorrect because the subject and direct object are reversed. The sentence “Our neighbor bitten by their dog yesterday” is also incorrect because the past participle “bitten” is used as an adjective to modify the noun “neighbor.” The sentence “Our neighbor were bit by their dog yesterday” is incorrect because the verb “to bite” requires a singular subject, and “our neighbor” is a plural noun.
The sentence “Our neighbor was bitten by their dog yesterday” is correct because it uses the past tense of the verb “to bite” and the singular subject “our neighbor.” It also uses the correct verb tense to indicate that the action of biting occurred in the past.