Production possibility curves — practice question

The diagram illustrates a production possibility curve for goods X and Y. Which combination is correct for the opportunity cost of producing more of good Y and for the opportunity cost of producing more of good X?

• Aopportunity cost of producing more of good Y decreases; opportunity cost of producing more of good X decreases
• Bopportunity cost of producing more of good Y decreases; opportunity cost of producing more of good X increases
• Copportunity cost of producing more of good Y increases; opportunity cost of producing more of good X decreases
• Dopportunity cost of producing more of good Y increases; opportunity cost of producing more of good X increases