Given below are six sentences, out of which sentences A and F are in the correct position. Sentences B, C, D and E are in a jumbled order. Select the option that gives the correct order.

A. In Jhum cultivation, a patch of land is cleared, and vegetation is burned.
B. The same practice is repeated elsewhere on a fresh piece of land.
C. Then this area is abandoned and is left to recover its fertility. 
D. This patch of land is used for raising crops for two to three years, and the yield is modest.
E. Then the ash is mixed with the soil thus adding nutrients to the soil.
F.  All that is required for this method of cultivation is a set of simple tools, not a high level of mechanization.