Nanak met his brother in the street. He asked him where he was going.
The correct option is A Having met his brother in the street, Nanak asked him where he was going.
The sentences in the question indicate the sequence of actions taking place. Nanak met his brother first, then asked him where he was going. That is why we have to use "having met...", because both the events are not taking place at the same time. In option B, the form of the verb "having meeting" is a wrong one. In English, we never say "having meeting" - it is an incorrect formation. In options C and D, the sequence is reversed.