The correct answer is B.

It's not true that the export supply curve is flatter than the domestic supply curve in the exporting country.

The export supply curve is a curve that indicates the changes and the differences between the quantity supplied by foreign producers or suppliers and the quantity demanded by foreign customers. The export supply curve changes regularly than the domestic supply curve due to changes in other countries' interest rates, exchange rates, tariffs, and production levels. All these are the factors that influence supply and demand of exports and imports in a particular country. An increase in the given factors reduces demand and supply while a decrease increases foreign products' demand and supply.