As a factor of production, land best refers to

A. the ground not covered by water

B. land owned by businesses

C. all natural resources

D. farming soil only

The first factor of production is land, but this includes any natural resource used to produce goods and services. This includes not just land, but anything that comes from the land. Some common land or natural resources are water, oil, copper, natural gas, coal, and forests.

So I'm assuming the answer would be:

C. All natural resources