Final answer:
The hedge fund can be discussed with the couple with a joint annual income of $400,000 and the young investor with a net worth of $500,000 and an annual income of $150,000.
Step-by-step explanation:
Under Regulation D, which governs private placements, the hedge fund can only be discussed with accredited investors.
An accredited investor is an individual or entity that satisfies certain income and/or net worth requirements.
Based on the information provided, the middle-aged couple who are both physicians with a joint annual income of $400,000 and the young, aggressive investor with a net worth of $500,000 and an annual income of $150,000 would be eligible to discuss the fund as potential clients.