What is the cause ____________ the problem?
- A. of
- B. on
- C. about
- D. in
Explanation
The fixed combination is “the cause of something,” as in “the cause of the problem.” The other prepositions do not complete this expression correctly.
Explanation
The fixed combination is “the cause of something,” as in “the cause of the problem.” The other prepositions do not complete this expression correctly.