The answer is "A. Mutual funds".
A mutual fund is a professionally overseen investment support that pools cash from numerous speculators to buy securities. These speculators might be retail or institutional in nature.
Mutual funds have points of interest and drawbacks contrasted with direct putting resources into individual securities. The essential favorable circumstances of mutual funds are that they give economies of scale, a larger amount of broadening, they give liquidity, and they are overseen by expert financial specialists. On the negative side, financial specialists in a mutual funds must pay different charges and costs.