The Gobindgarh Fort, now a museum, is located in:

The correct answer is: a) Jalandhar

Gobindgarh Fort is a fort in the city of Jalandhar, Punjab, India. It was built in 1763 by Nawab Kapur Singh, the founder of the Sikh Misl of Kanhaiya Misl. The fort was later captured by Maharaja Ranjit Singh in 1799 and became one of the most important forts in the Sikh Empire.

The fort is now a museum and is open to the public. It is one of the most popular tourist attractions in Jalandhar.

The other options are incorrect because:

• Patiala is a city in the Indian state of Punjab. It is the capital of the Patiala district and the Patiala division.
• Amritsar is a city in the Indian state of Punjab. It is the holiest city of the Sikh religion and the headquarters of the Shiromani Gurdwara Parbandhak Committee (SGPC).
• Ludhiana is a city in the Indian state of Punjab. It is the largest city in the state and the second-largest city in the northwestern region of India.