In which sentence does the subject correctly agree with the verb?

In choice B, the subject is “branches,” which is plural, and it correctly takes the plural verb “are.” In A, the singular subject “cactus” should take “has,” not “have.” In C, “either the woody ribs or the hollow ‘saguaro boots’” refers to plural items, so it should take “are used.” In D, the plural subject “Temperature and elevation” should take “affect,” not “affects.”

AI-written and checked against the verified answer.