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