Which of the following is not generally considered to be a resource​ (factor of​ production)?  

A.
Upper A coal mine
.
B.
Upper A U.S. Treasury bond
.
C.
An accountant
.
D.
Upper A manager at a chair factory
.

B. Upper A U.S. Treasury bond

The correct answer is B. A U.S. Treasury bond.

Explanation:

A resource, also known as a factor of production, refers to any input used in the production process. The three main types of resources are land/natural resources, labor, and capital.

Option A, an Upper A coal mine, refers to a natural resource, which is a type of land resource.

Option C, an accountant, refers to labor, which represents human effort and skills.

Option D, a manager at a chair factory, is also a labor resource.

However, option B, a U.S. Treasury bond, is not generally considered a resource or factor of production. A U.S. Treasury bond represents a financial instrument or investment, which falls under the category of capital resources, rather than a traditional factor of production.