请教一道GMAT语法题,实在是看不懂~
For the farmer who takes care to keep them cool,*providing them with high-energy feed,and milking them regularly,Holstein cows are producing* an average of 2,275 gallons of milk each per year.
A.providing them with high-energy feed,and milking them regularly,Holstein cows are producing
B.providing them with high-energy feed,and milked regularly,the Holstein cow produces
C.provided with high-energy feed,and milking them regularly,Holstein cows are producing
D.provided with high-energy feed,and milked regularly,the Holstein cow produces
E.provided with high-energy feed,and milked regularly,Holstein cows will produce
为什么一开始要说for the farmer...这个句子的主语却是cows.还有,为什么A不对.