Alvin's Preferences for Good X and Good Y Are Shown

Multiple Choice

Alvin's preferences for good X and good Y are shown in the diagram below. Figure 3.2
-Refer to Figure 3.2. At any consumption bundle with the quantity of good X exceeding the quantity of good Y (that is, a bundle located below the 45 degree line, like point A, Alvin's marginal rate of substitution of good X for good Y is

A) diminishing.
B) positive.
C) constant and positive.
D) zero.