Suppose that a consumer consumes only two goods, good x and good y. Assume that (q=20, I=50) and (q'=23, I'=60) are two points on the consumer's Engle curve for good x. Assume that good y is a normal good. Which of the following statements is true?
A. The income elasticity of good y is negative.
B. The income elasticity of good x is positive.
C. The income consumption curve between good x and good y has a negative slope.
D. The Engel curve for good y has a negative slope.
E. None of the above.