Most Advanced Nations Have Both Agricultural Sectors and Armaments Industries

Essay

Most advanced nations have both agricultural sectors and armaments industries. They do not completely specialize in one industry or the other; but generally produce some of both commodities.
(a) State the principle of increasing marginal opportunity cost.
(b) Is this incomplete specialization consistent with the principle of increasing opportunity costs? Explain your answer in the context of the tradeoff between guns and butter.