Consider the following statements about the frontier policies of the Delhi Sultanate:
- The Khiljis and Tughlaqs undertook military campaigns to consolidate the northwestern frontiers against Mongol invasions.
- Fortresses were established along the borders to protect against external threats.
- The Delhi Sultanate maintained an aggressive frontier policy, constantly expanding its territory in the Deccan.
- Control over trade routes along the frontier was a key objective of the Sultanate’s frontier policy.
Which of the above statements is/are correct?
1
1, 2, and 3
2
2 and 3 only
3
1 and 4 only
4
1, 2, and 4