An Economy Can Produce Either of These Two Combinations of Goods

Multiple Choice

An economy can produce either of these two combinations of goods X and Y: 1,000X and 0Y or 400Y and 0X.Furthermore,the opportunity cost between the two goods is always constant.Which of the following combinations of the two goods,X and Y,lies on the economy's production possibilities frontier?

A) 700 units of X and 280 units of Y
B) 600 units of X and 250 units of Y
C) 400 units of X and 150 units of Y
D) 90 units of X and 360 units of Y
E) 300 units of X and 280 units of Y