If This Economy Produces More Than 20 Houses Per Year,the

If this economy produces more than 20 houses per year,the opportunity cost of a house will ________ because ________.

A) decrease; production will be specialized
B) increase; an input with a higher opportunity cost must be used
C) decrease; inputs will be obtained at lower costs
D) increase; all gains from trade have already been exploited
E) remain the same; Amy and Jim produce in constant ratios regardless of the level of output