Final answer:
The investment return of a variable annuity is based on the performance of the separate account.
Step-by-step explanation:
The variable annuity's investment return each month is based on the performance of the separate account (option B) in this case.
A variable annuity is a type of investment account that allows the investor to choose from a variety of investment options, known as separate accounts, which may include stocks, bonds, or other assets.
The returns on these separate accounts determine the investment return of the variable annuity.