Why do african farmers practice “slash and burn” farming?
a.
it is the most environmentally responsible method available
b.
the crops produced by this method are more nutritious, which increases their price
c.
this method to fertilize the land, increasing production
d.
it decreases deforestation and desertification

C.  this method helps to fertilize the land, increasing production

Explanation:

This method of clearing fields, called "slash and burn" is a method of agriculture primarily used by tribal communities for subsistence farming (farming to survive). Humans have practiced this method for about 12,000 years, ever since the time when humans stopped hunting and gathering and started to stay put and grow crops. Today up to 7% of the world’s population uses slash and burn agriculture.

Resource: Jenner, Lynn. “Agricultural Fires Across Africa.” NASA, NASA, 25 June 2013