Identify the sentence that has a problem in subject-verb agreement.
a.
the most dedicated volunteers at our local homeless shelter were once homeless themselves.
b.
the sales tax increase, although not favored by some business owners, was overwhelmingly voted in by the legislature.
c.
handheld devices, including cell phones and tablets, are rapidly replacing personal computers for many users.
d.
many musicians, including unlikely candidates such as elvis presley, has been influenced by gospel music.

D) Many musicians, including unlikely candidates such as Elvis Presley, has been influenced by gospel music.

Explanation: Subject-verb agreement means the subject and verb must have the same number (both singular or both plural). From the given options, the sentence that has a problem in subject-verb agreement, is the corresponding to option D: Many musicians, including unlikely candidates such as Elvis Presley, has been influenced by gospel music, because the subject is "many musicians" (plural subject) and the verb is "has" (singular subject), it should be "have."