Suppose a consumer has $100 to spend on two goods, shoes and shirts. If the price of a pair of shoes is $20 per pair and the price of a shirt is $15 each, which of the following combinations is unaffordable ( ) to the consumer?

A. 5 pairs of shoes and 0 shirts

B. 0 pairs of shoes and 7 shirts

C. 2 pairs of shoes and 4 shirts

D. 2 pairs of shoes and 3 shirts