Infrastructure, skilled labor, and capital are examples of

a. relating and supporting industries

b. domestic demand conditions

c. firm strategy, structure, and rivalry

d. factor endowments

The answer would be factor endowments. It is because factor endowments is based on what the country has or possess in terms of the labor, capital and land that they acquire. It is also used for manufacturing and how much the country could exploit in regards to this factors. It is related to the given statement above so the answer would be letter D.