The correct answer is A, Open-end fund. An open-end fund, commonly known as a mutual fund, is an investment company that is actively managed by a portfolio manager and continuously offers new shares to investors. This means that investors can buy shares directly from the fund at the fund’s net asset value (NAV) at the end of each trading day, and the fund will issue new shares to meet demand.

A key characteristic of open-end funds is that they are continuously offered, unlike closed-end funds, which issue a fixed number of shares in an initial public offering (IPO) and then trade on the secondary market like stocks. Additionally, open-end funds are typically actively managed, meaning the portfolio manager makes ongoing decisions to buy and sell securities in an effort to meet the fund’s investment objectives.

Choice B, Closed-end fund, is incorrect because these funds are not continuously offered and trade in the secondary market. Choice C, Variable annuity, is an insurance product, not an investment company under the Investment Company Act in the same way. Choice D, UIT, is not actively managed; it has a fixed portfolio.

Thus, the description clearly matches an open-end fund, making choice A correct.