Answer:
A prospectus is not required because the initial public offering happened 5 years ago
Explanation:
A prospectus is a legal document which is to be filled by Securities and Exchange Commission (SEC) that reflects the details with respect to the investment offering to the public in terms of stocks, bond, mutual funds, etc
On the other hand the initial public offering is the offering done by the company for the first time to the public related to the investment
Since in the question it is mentioned that the customer purchased the shares of stock but its initial public offering is done 5 years ago so no prospectus is required
