The Price of X Is $20 and the Price of Y

Multiple Choice

The price of X is $20 and the price of Y is $40.


-Based on the above graph,at point B,

A) if the consumer obtains one more unit of Y,½ unit of X must be foregone in order to keep utility unchanged.
B) if the consumer obtains one more unit of X,two units of Y must be foregone in order to keep utility unchanged.
C) the marginal rate of substitution is ½.
D) both a and c
E) all of the above