He can solve this problem. (Passive)

  1. This problem can be solved by him.
  2. This problem can solved by him.
  3. This problem can be solve by him.
  4. This problem could be solved by him.
Answer

A) This problem can be solved by him.

can + be + V3. Active & Passive Voice · Voice with modals & imperatives

English MCQ · More English: Active & Passive Voice MCQs · Practise