Suppose one factory produces residential windows and doors. The following scenarios describe various

straight-line production possibilities boundaries for this factory. Each scenario describes the numbers of

doors that could be produced in one day if all the factory's resources were devoted to producing doors and

the number of windows that could be produced in one day if all the factory's resources were devoted to producing

windows. For each scenario, calculate the opportunity cost to the factory owner of producing one extra door.

a. 1000 windows; 250 doors

b. 500 windows; 500 doors

c. 1200 windows; 400 doors

d. 942 windows; 697 doors

e. 450 doors; 600 windows