Production possibilities(alternatives)
P Q R S T
Units of shelter 5 4 3 2 0
Units of food 0 5 9 12 15

Based on the above production possibilities table, the real cost of a unit of food when alternative R is selected is?

• A.one unit of shelter
• B.three units of shelter
• C.one third of a unit of shelter
• D.six units of shelter
• E.two units of shelter