求指教！ Old prep sc 95

Kclaire

Unlike frogs that metamorphose from tadpoles into adults within a one-year period, it takes three to
four years for the mountain yellow-legged frog of the Sierra Nevada to reach adulthood, and so they
are restricted to deeper bodies of water that do not dry up in summer or freeze solid in winter.

(A) it takes three to four years for the mountain yellow-legged frog of the Sierra Nevada to reach
adulthood, and so they are
(B) it takes the mountain yellow-legged frog of the Sierra Nevada three to four years until it reaches
adulthood, and therefore it is
(C) in the Sierra Nevada, mountain yellow-legged tree frogs take three to four years to reach
adulthood, thus being
(D) mountain yellow-legged frogs of the Sierra Nevada take three to four years until they reach
adulthood, thus
(E) mountain yellow-legged frogs of the Sierra Nevada take three to four years to reach adulthood,
and so they are


For choice D, 答案上有说伴随状语这里不符合逻辑，不是很明白这个，请高人指点！