In which sentence does the subject agree with the verb?

A. A herd of elephants move slowly across the savanna, the youngest weaving between legs of their mothers.
B. The flock if sheep scurry down the path, nudged on by the border collies running beside them.
C. The team of horses runs across the prairie, startling the sunbathing birds.
D. A band of coyotes roam the forest next to the lake, occasionally coming to the shore for a drink.

D. A band of coyotes roam the forest next to the lake, occasionally coming to the shore for a drink.

The sentence in which the subject agrees with the verb is:

B. The flock of sheep scurry down the path, nudged on by the border collies running beside them.