A question in GMAT Sentence Correction(885)

simonhuang

In question "In the face of widespread concern about environmental waste, compact disc manufacturers are attempting to find a replacement for the disposable plastic box in which they package their product", why answer (A)"the disposable plastic box in which they" is better than answer (B)"the disposable plastic box where they"?
thanks.

edy_25

(B)"the disposable plastic box where they"? means they stand in the box packing their product

merlion

OG 137. In 1982 the median income for married-couple families with a wage-earning wife was $9,000 more than a family where the husband only was employed.
(A)    a family where the husband only
(B)    of a family where only the husband
(C)    that for families in which only the husband
(D)    a family in which only the husband
(E)    those of families in which the husband only

og 的解释：In A and B, in which would be preferable to where, since where properly refers to location.