15.B In good years, the patchwork of green fields that surround the San Joaquin Valley town bustles with farm workers, many of them in the area just for the season.
(A) surround the San Joaquin Valley town bustles with farm workers, many of them
(B) surrounds the San Joaquin Valley town bustles with farm workers, many of whom are
(C) surround the San Joaquin Valley town bustles with farm workers, many of who are
(D) surround the San Joaquin Valley town bustle with farm workers, many of which（A）
(E) surrounds the San Joaquin Valley town bustles with farm workers, many are
B对不对？我知道A更好，但我想知道B是否是对的 | 
