-The Figure Above Shows the Production Possibilities Frontier for a Country.If

-The figure above shows the production possibilities frontier for a country.If the economy is operating at point B,then the opportunity cost of another million litres of milk is

A) 1 litre of ice cream for a litre of milk.
B) 3 litres of ice cream for a litre of milk.
C) 4 litres of ice cream for a litre of milk.
D) 1/3 of a litre of ice cream for a litre of milk.
E) zero because after producing another million litres of milk then zero litres of ice cream are produced.