ALTHOUGH LONDON IS FAR FROM BEING AN UNPOLLUTED CITY, THE PROBLEM...

48. Although London is far from being an unpolluted city, the problem isn't as bad as it used to be.

A. Compared to its situation in the past, these days there is hardly any pollution in London.

B. London is undoubtedly still polluted, but it's less of a problem because people are accustomed to it now.

C. London isn't as polluted as it was in the past, in fact, the pollution problem has been solved.

D. While the problem definitely hasn't disappeared, there is less pollution in London nowadays.