TN-12 求指教

Richardyu

For the farmer who takes care to keep them cool, providingthem with high-energy feed, and milking them regularly, Holstein cows areproducing an average of 2,275 gallons of milk each per year.

A.   providing them with high-energy feed, and milkingthem regularly, Holstein cows are producing

B.    providing them with high-energy feed, and milkedregularly, the Holstein cow produces

C.   provided with high-energy feed, and milking themregularly, Holstein cows are producing

D.   provided with high-energy feed, and milkedregularly, the Holstein cow produces

E.    provided with high-energy feed, and milkedregularly, Holstein cows will produce

为什么不是选E, 不选A（cows are producing 不好，除了这个还有其它原因吗？）