In a certain area where there are many farms, the groundwater levels have dropped by as much as 10 m over a period of 30 years. The main cause behind this is MOST LIKELY

A)the evaporation of water from aquifers.

B)the excessive pumping of water through wells.

C)the leakage of fertilizers from the farms into the aquifer.

D)the construction of a dam to divert water into a reservoir