If Perfect Competition Prevails in a Two Good (X and Y)and

If perfect competition prevails in a two good (X and Y) and two input (L and K) economy,all of the following conditions are satisfied,except that:

A) the price of good X is equal to the price of good Y.
B) the marginal cost of producing good X is equal to the price of good X.
C) the marginal rate of substitution between X and Y is equal to the marginal rate of transformation.
D) the ratio of the marginal costs of the inputs is equal to the input price ratio.