Answer: C)Comparing marginal costs and marginal benefits.
Explanation: Ration person is the person that has reasonable way of thinking. The individual usually takes every decision in the a sound way according to the facts. The person taking the decision regarding the margin will make decision on the basis of the actual facts and figure involved in the marginal benefit.
Other option are incorrect because they show rationality on the basis of the traditions,color,and fashion which is not related with cost and margin.Thus, the correct option is option(C) .
