The air quality in Beijing as well as in the neighboring cities we once spent much time______ better and better.

1. A.
   in getting
2. B.
   having got
3. C.
   in is getting
4. D.
   has got

The air quality in Beijing as well as in the neighboring cities we once spent much time____ better and better.

A. in getting   B. having got  C. in is getting       D. has got