There is a new problem involved in the popularity of private cars_______ road conditions need to be improved

1. A.
   that
2. B.
   which
3. C.
   where
4. D.
   when

There is a new problem involved in the popularity of private cars_______ road conditions need to be improved.

A.that                   B.which                C.where                D.when

There is a new problem involved in the popularity of private cars ____________ road conditions need ____________.

A. that; to be improved          B. which; to be improved  

C. where; improving              D. when; improving

There is a new problem involved in the popularity of private cars ____________ road conditions need ____________.

  A. that; to be improved B. which; to be improved   C. where; improving D. when; improving

There is a new problem involved in the popularity of private cars _______ road conditions need _______.

  A. that; to be improved B. which; to be improved   C. where; improving D. when; improving