which of the following statements is correct regarding types of income?

A- If the income is not from personal services, the income must be classified as investment.

B- Income must always be classified as either investment income, self-employment income, or employee compensation income.

C- Interest earned on excess working capital of a business is trade or business income, rather than Category 1 income.

D- Some types of income are not subject to either the social security tax or the NII tax.