The correct option is B He had surrendered the fort at Kasur.
Qutub-ud-Din, son of Nizam-ud-din of Kasur, violated Ranjit Singh's trust by forming an alliance with Muzzafar Khan, the ruler of Multan. Ranjit Singh invaded Kasur, besieged the fort and made Qutub-ud-Din surrender. He was given Jagir of Mamdot for his livelihood.