Which of these statements is $($are$)$ TRUE? I. The NASDAQ is an example of a mutual fund. II$.$ All else equal, expected returns on different assets adjusted for risk should not be equal. III. The rule of $70$ states that if the annual rate of return of an investment is x$\%,$ it will take $(70-$: x$)$ years for the value of the investment to double.

I only

I and III only

II only

III only