Which of the following types of income are included in qualified business income (QBI)? Oa. Income generated from a qualified trade or business. Ob. Guaranteed payments made in compensation for services performed by a partner to a partnership. Oc. Income earned from foreign business operations. Od. Wages paid to an employee. Classify the following items as a "Primary sources" or "Secondary sources" for the purpose of substantial authority. a. Temporary Regulations. Revenue Procedures. b. c. d. Treasury Decisions (TDs). Determination letters. e. A technical advice memorandum