[SC悬赏令] KD的GMAT疑惑之语法001

20. GWD26-Q20

In 1981 children in the United States spent an average of slightly less than two and a halfhours a week doing householdchores; by 1997 they had spent nearly six hours a week.

A.   chores; by 1997 they had spent nearly sixhours a week

B.   chores; by 1997 that figure had grown tonearly six hoursa week

C.   chores, whereas nearly six hours a week were spent in 1997

D.   chores, compared with a figure of nearly sixhours a week in 1997

E.    chores, that figure growing to nearly sixhours a week in 1997