Final answer:
Customer Payment (Reg T) for corporate securities in a cash or margin account must be made within two business days after the trade date (T+2).
Step-by-step explanation:
The correct answer is B) T+2 (two business days after the trade date).
Regulation T, also known as Reg T, is a regulation set by the Federal Reserve Board that governs the amount of credit an investor can use to buy securities. According to Reg T, customer payment for corporate securities in a cash or margin account must be made within two business days after the trade date (T+2).