Answer:
D. Victor plays the piano almost every afternoon
Step-by-step explanation:
Subject-verb agreement occurs when a singular subject is followed by a singular verb, or when a plural subject is followed by a plural form verb. In that respect, the sentence contains a singular subject, Victor, and a singular verb, plays.
The rest of the sentences are incorrect because they contain subjects and verbs which do not match in number. The correct version is the following:
A. The children go to bed later durning the summer.
B. Fiona and Robert are riding the bus to the park this afternoon.
C. They wash the car on sunny weekend days.