An Apple Orchard Has an Average Yield of 36 Bushels

Multiple Choice

An apple orchard has an average yield of 36 bushels of apples/tree if tree density is 21 trees/acre. For each unit increase in tree density, the yield decreases by 2 bushels. Letting x denote the number of trees beyond 21/acre, find a function in x that gives the yield of apples. ​

A) f(x) = (21 + x) (36 + 2x)
B) f(x) = 2(21 + x) (36 - x)
C) f(x) = 2(21 - x) (36 - 2x)
D) f(x) = (21 - x) (36 + 2x)
E) f(x) = (21 + x) (36 - 2x)