The correct passive form: I know him.
He is known by me
He was known to me
He was been known by me
He is known to me
সঠিক উত্তর:
He is known to me
ব্যাখ্যা ও নোট:
Know verb এর পর preposition হিসেবে by না বসে to বসে এবং present tense হওয়ায় is known হয়েছে।