Which is a man-made resource? A. land B. crude oil C. tools D. entrepreneurship E. biomass

To determine which option represents a man-made resource, let's analyze each choice.

1. A. Land - This is a natural resource and not man-made.
2. B. Crude oil - This is also a natural resource extracted from the earth.
3. C. Tools - These are created by humans to aid in various tasks and are considered man-made resources.
4. D. Entrepreneurship - This refers to the act of starting and managing a business, which is a human endeavor but not a physical resource.
5. E. Biomass - This is a natural resource derived from organic material.

Based on this analysis, the correct answer is C. tools, as they are created through human effort and ingenuity.