Point a on a Linear Production Possibilities Curve Represents a Combination

Multiple Choice

Point A on a linear production possibilities curve represents a combination of 12 coffees and 3 cappuccinos, and point B represents 3 coffees and 6 cappuccinos. Suppose coffees are on the vertical axis and cappuccinos are on the horizontal axis. The opportunity cost of a cup of coffee is:

A) 3 cappuccinos
B) 9 cappuccinos
C) 1/3 of a cappuccino
D) 6 cappuccinos