Final answer:
The cash deposit required for an initial purchase of $3,000 of common stock in a margin account is $1,500.
Step-by-step explanation:
The correct answer is B. $1,500.
Under industry regulations, an initial purchase of $3,000 of common stock in a margin account requires a cash deposit equal to 50% of the purchase amount. So, in this case, 50% of $3,000 is $1,500. Therefore, the cash deposit required would be $1,500.