Swiss Exports Are Concentrated,high-Density Products (Cheese,chocolates,watches)that Minimize the Need for Importing

Swiss exports are concentrated,high-density products (cheese,chocolates,watches) that minimize the need for importing bulky materials because:

A) mountain ranges increase transport costs in and out of Switzerland and limit local resources.
B) the Swiss love of chocolate and watches influenced the export patterns.
C) high density exports encounter lower tariffs.
D) the Swiss chose not to have a strong agricultural base for an export strategy.