Because of wireless service costs plummeting in the last year, and as mobile

Phones are increasingly common, many people now using their mobile phones

To make calls across a wide region at night and on weekends, when numerous

Wireless companies provide unlimited airtime for a relatively small monthly fee.

A.     Because of wireless service costs plummeting in the last year, and as

Mobile phones are increasingly common, many people.

B.     As the cost of wireless service plummeted in the last year and as mobile

Phones became increasingly common, many people.

C.     In the last year, with the cost of wireless service plummeting, and mobile

Phones have become increasingly common, there are many people.

D.     With the cost of wireless service plummeting in the last year and mobile

Phones becoming increasingly common, many people are

E.      While the cost of wireless service has plummeted in the last year and

Mobile phones are increasingly common,  many people are.

 the correct is d,but i want to know why e is incorrect?why not "while"?

仔细看了看其他的资料，觉得不应该是Ｄ．．．．理由还不确定，等确定了再贴上来