PT 37 S4 Q25

In ancient Mesopotamia, prior to 2900 B.C., wheat was cultivated in considerable ... ...

Which one of the following, if true, most helps to support the historians' contention concerning the reasons for the decline in wheat production in ancient Mesopotamia?
(A) The cultivation of barley requires considerably less water than does the cultivation of wheat.
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Practice Set: "Stronger" Questions, Set 3 - Difficult/Uncommon Mix (25Q)