Arrange the following key developments in Harappan civilization in the correct chronological order.
- The beginning of the cities around 4700 years ago.
- The cultivation of cotton at Mehrgarh about 7000 years ago.
- The decline of the cities around 3900 years ago.
- Construction of fire altars at Kalibangan and Lothal.
1
1,2,3,4
2
2,1,4,3
3
3,1,2,4,
4
4,1,2,3