Which sentence displays correct subject-verb agreement?

A. The books at the library is very helpful
B. My collection of stamps is extensive
C. The island visited by the travelers are warm
D. The cattle in the field is huge!

B. My collection of stamps is extensive.

The sentence that displays correct subject-verb agreement is B. "My collection of stamps is extensive."

To determine the correct subject-verb agreement, we must ensure that the subject and the verb in the sentence agree in number. In this case, the subject is "My collection of stamps," which is singular. Therefore, the verb "is" is also singular, making the sentence grammatically correct.

The sentence that displays correct subject-verb agreement is B. My collection of stamps is extensive.