In World of Two "Large" Countries, If One Country Imposes

Multiple Choice

In world of two "large" countries, if one country imposes a tariff, the welfare of the Tariff-imposing country will definitely improve (assuming no retaliation) if, the tariff-Imposing country

A) is trading, both before and after the imposition of the tariff, in the "elastic" portion of Its trading partner's offer curve.
B) is trading, both before and after the imposition of the tariff, in the "inelastic" portion Of its trading partner's offer curve.
C) is putting the new tariff on top of an already existing tariff rate that is greater than the "optimum" tariff rate.
D) puts on a prohibitive tariff.