What primarily determines the NAV of a mutual fund?

The Net Asset Value (NAV) of a mutual fund is primarily determined by the total value of the fund's assets minus its liabilities. This concept is fundamental in understanding how mutual funds are valued.

Assets include all the securities the fund holds, such as stocks and bonds, as well as any cash or cash equivalents. Liabilities could involve management fees, outstanding expenses, and any money owed by the fund. Thus, by subtracting the total liabilities from the total assets, you can calculate the NAV, which represents the per-share value of the fund. This value is crucial because it helps investors understand how much a share of the fund is worth at any given time and is the basis for transactions when they buy or redeem shares.

In the context of the other options, the fund's market position, the number of investors, and its historical performance may influence investor sentiment and demand for the fund, but they do not directly determine the NAV. The NAV itself is a calculation based solely on the fund's current asset values and its liabilities, making option C the correct answer.