问题
Wow, useful and fashionable iphone 6s you have bought!—Yes, it is ____ great help to me, ____ I must say it also cost me a lot.
A:What, a, but
B:What an, the, and
C:What a, a , and
D:How, a ,but;
B:What an, the, and
C:What a, a , and
D:How, a ,but;
正确答案是：
