আমি এটা না করে পারলাম না ।
ক
I could not help do it
খ
I could not help doing it
গ
I could not help to do it
ঘ
I could not but did it
সঠিক উত্তর: I could not help doing it
বাক্যে can not help থাকলে verb এর সাথে ing যোগ করতে হয়। এইজন্য - I could not help doing it.