Which of these countries is benefitting through gains from trade?

Country F imports component parts from Country $G$ and uses them to build automobiles that it exports back to Country $G.$

Country A exports small appliances but it imports cereal and dairy products from Country B because Country B produces them more efficiently.

Country $C$ exports all of its agricultural products at a high price and then imports those same products at a lesser cost.

Country $D$ and Country $E$ share a border and trade between each other to avoid import fees.