I know that he did the work- বাক্যটির সঠিক পরিবর্তিত voice কি হবে?

• ক It was known to me that the work had been done by him.
• খ It is known to me that the work was done by him. ✅ সঠিক উত্তর
• গ It was known to me that the work has been done by him.
• ঘ It was known to me that the work was done by him.