Which of the following is not a "trade or business" expense?

A. Mortgage interest on a warehouse
B. Depreciation on business equipment
C. Mortgage interest on a personal residence
D. Cost of goods sold

is it C

Yes, C.

Yes, you are correct. Option C - Mortgage interest on a personal residence is not considered a "trade or business" expense.

To determine the answer, let's break down the options:
A. Mortgage interest on a warehouse - This expense relates to a business property, so it can be considered a "trade or business" expense.
B. Depreciation on business equipment - Depreciation on business equipment is a legitimate "trade or business" expense since it pertains to the cost allocation of business assets.
C. Mortgage interest on a personal residence - This expense is related to a personal residence, not a business. Therefore, it is not considered a "trade or business" expense.
D. Cost of goods sold - Cost of goods sold is a fundamental expense directly associated with the production or creation of goods or services for sale, making it a legitimate "trade or business" expense.

By analyzing the options, we can conclude that option C is not a "trade or business" expense.