Ginger and Maryann are lost in the jungle, where the only things to eat are mangoes and fish. Ginger can gather more mangoes per hour than Maryann and can also catch more fish per hour than can Maryann. Therefore:

A、Ginger should specialize in the activity for which she has an absolute advantage.;

B、Maryann should specialize in the activity for which she has a comparative advantage.;

C、There are no gains to specialization and trade for Maryann.;

D、There are no gains to specialization and trade for Ginger.