A farmer has 120 acres of land on which he wants to grow corn and soybeans. It requires 20 acre-inches (inches of water per acre per year) to grow corn and 23 acre-inches to grow soybeans, and the farmer has 2500 acre-inches of irrigation water available. Which of the following combinations of acres of corn and soybeans will allow the farmer to meet his water and corn restrictions while farming the most acres of land?
A.50 acres of corn and 70 acres of soybeans
B.70 acres of corn and 40 acres of soybeans
C.80 acres of corn and 40 acres of soybeans
D.90 acres of corn and 30 acres of soybeans
Choice D is correct.