Which of the following instructs a function to return the contents of the decStateTax variable?

The correct answer is A. Return decStateTax.

The keyword Return is used to return a value from a function. The value that is returned can be a variable, an expression, or a constant. In this case, the value that is returned is the contents of the variable decStateTax.

The keyword ByVal is used to pass a value by value. This means that the value of the variable is copied to the function, and any changes that are made to the variable in the function do not affect the variable in the calling code.

The keywords Send and SendBack are not used in Visual Basic.