A$.$

Expected return is the return expected on an asset during a future$$ period, while risk is the degree of uncertainty in the return on an asset.

B$.$

Expected return is the price of an asset a year from$$ now, while risk is the degree of uncertainty in the return a year from now.

C$.$

Risk is the return expected on an asset during a future$$ period, while expected return is the degree of uncertainty in the return on an asset.

D$.$

Risk is the price of an asset a year from$$ now, while expected return is the degree of uncertainty in the return a year from now.