The correct answer is a) Patiala.
Patiala was the largest and most powerful feudatory state in Punjab. It was founded in 1763 by Maharaja Ala Singh, who was a prominent Sikh warrior. The state reached its peak under the rule of Maharaja Narinder Singh, who ruled from 1801 to 1839. During his reign, Patiala became a major power in the region and played a key role in the Sikh Empire.
The other options are incorrect because they were not as large or powerful as Patiala. Malerkotla was a small state that was founded in 1665 by Nawab Fateh Khan. Jind was a small state that was founded in 1763 by Maharaja Gajpat Singh. Kapurthala was a small state that was founded in 1753 by Maharaja Jassa Singh Ahluwalia.
Patiala was the largest and most powerful feudatory state in Punjab because it had a strong military, a large population, and a prosperous economy. The state was also well-governed, which helped to ensure its stability and prosperity.