Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information. A. Human efforts to increase yields of wild grains relieved the pressure population growth put on the resource base of the area. B. The resource base of the area was pressured by population growth because third-choice foods were difficult to harvest and process. C. Although wild grains responded to human efforts to increase yields, they were third-choice foods because they were difficult to harvest and process. D. Population growth put pressure on available food resources, forcing people to eat foods that were less preferred but that responded to human efforts to increase yields.