Which of the following was/were steps taken by Sher Shah to promote trade and commerce?
1. Making travel safe for trader.
2. Building a new highway between Delhi and Warangal.
3. Abolishing internal duties and levying taxes only at the points of import and sale.
4. Building sarais along roadways.
(a) 1, 2 and 3 (b) 2 and 3 (c) 1, 3 and 4 (d) 1, 2, 3 and 4
