Who gave you this pen? বাক্যের Passive form —–

1. By whom were you got this pen?
2. By whom were you given this pen?
3. By whom was you given this pen?
4. By whom have you given this pen?

Answer: By whom were you given this pen?

Explanation: Who যুক্ত interogative sentence কে passive করার সময় By whom + be verb + subject + vpp + preposition + object .