The correct answer is B, diverse investments with end-of-day trading and pricing. An open-end mutual fund pools money from many investors and invests in a diversified portfolio of securities, such as stocks, bonds, or other assets, depending on its investment objective. A key feature of open-end funds is that they are priced once per day, after the market closes, based on the fund’s net asset value (NAV).

Investors buy and redeem shares directly from the fund company, not in the secondary market. All transactions occur at the end-of-day NAV, regardless of when the order is placed during the trading day.

Choice A is incorrect because intraday trading applies to exchange-traded funds (ETFs), not mutual funds. Choice C describes a money market fund, which is a specific type of mutual fund focused on short-term debt instruments, not all open-end funds. Choice D describes characteristics of hedge funds or private investments, which are illiquid and often charge performance fees.

Thus, the defining features of open-end mutual funds are diversification and end-of-day pricing, making choice B the correct answer.