I helped her solve the problem. (Passive)

A She was helped solve the problem.

B The problem was solved by me.

C Her problem was solved by me.

D She was helped to solve the problem by me.

Correct Answer: Option D

Bare infinity যুক্ত sentence কে passive করতে obj. কে sub. + was + verb3 + to + verb + on + by + sub এর objective form হয়। অতএব সঠিক উত্তর (4)।