The diagram below shows a production possibility curve (PPC) for an economy producing military goods and healthcare services.

The opportunity cost of increasing the output of healthcare services from H1 H_1\,H1 to H2 H_2\,H2 is shown by:
H2−H1H_2 - H_1H2−H1
M2−M1M_2 - M_1M2−M1
M2+M1M_2 + M_1M2+M1
M1−M2M_1 - M_2M1−M2