17. When two subjects are joined by "and," which verb form should be used? a. no verb needed b. singular verb only c. either singular or plural d. plural verb

d. plural verb<br /><br />When two subjects are joined by "and," a plural verb should be used because the combination of the two subjects is considered plural. For example, in the sentence "The cat and the dog are playing," the plural verb "are" is used.