The Opportunity Cost of Good a in Terms of Good

The opportunity cost of good A in terms of good B is equal to the

A) money price of good B minus the money price of good A.
B) ratio of the money price of good A to the money price of good B.
C) ratio of the money price of good B to the money price of good A.
D) money price of good A plus the money price of good B.
E) money price of good A minus the money price of good B.