Correct option is C
During the Delhi Sultanate, several frontier towns served as military posts to defend against invasions from the northwest, particularly from Mongol forces. Dipalpur, Lahore, and Multan were crucial military outposts used to secure the north-western frontiers. These cities acted as defensive bulwarks and strategic points for launching counter-attacks or resisting invasions. Debal and Kasur, while important in other contexts, were not the primary military posts against Mongol invasions during this period.
Information Booster:
The Delhi Sultanate faced repeated threats from the Mongols in the 13th and 14th centuries. The Sultanate established strong military garrisons in cities like Dipalpur, Lahore, and Multan to act as buffer zones preventing Mongol incursions into the heartland of India. Lahore, in particular, was a major administrative and military center. These forts and posts played a vital role in safeguarding the Sultanate's northern boundaries, contributing to the empire’s ability to maintain control despite frequent invasions.
Additional Knowledge:
Debal was a port city important in earlier Islamic conquests but not primarily a military post for Mongol defense during the Delhi Sultanate.
Kasur became prominent later under Mughal rule but was not a main military post against the Mongols during the Delhi Sultanate era.