Which sentence has an error in subject-verb agreement?
A) Sarah Conner, after playing with the neighborhood girls, fell asleep in the backyard hammock.
B) The teacher opened her door to find a police officer and drug dog outside waiting to come in.
C) Some employers--in fact, those who often have families of their own--give out yearly Christmas bonuses.
D) Joseph Schultz in the next apartment, as well as the entire Partridge family, have lived in our neighborhood since 1990.