The basin system of irrigation in the Nile Basin is not reliable because?

A. too much of the water percolates into the ground
B. only a few crops can be grown
C. it is not considered suitable by some farmers
D. too much labour is involved in making the basins
E. it depends on the flow of the Nile in a particular year

Correct Answer:

Option E – it depends on the flow of the Nile in a particular year