Which of the following geographic features was a primary factor that enabled the Sumerians to farm crops such as the barley mentioned in the administrative account shown above?

(A) The river valleys of the Tigris and Euphrates (B) The mountains of the Hindu Kush (C) The Nile Delta (D) The deserts of the Arabian peninsulaExplanation: Mesopotamia means “between the rivers”—those rivers being the Tigris and Euphrates. One of the primary factors that enabled the success of the Mesopotamians (and other early civilizations) was access to plenty of water and good soil. Choice (B) refers to a mountain range in South Asia; (C) refers to the major river in Egypt; and (D) doesn’t make sense because it is extremely difficult to grow crops in the desert. Therefore, the answer is (A).