13. Which of the following is false?

a. When you pass a variable by reference, the receiving procedure can change its contents.

b. To pass a variable by reference in Visual Basic, you include the ByRef keyword before the variable’s name in the Call statement.

c. When you pass a variable by value, the receiving procedure creates a procedure-level variable that it uses to store the value passed to it.

d. Unless you specify otherwise, a variable in Visual Basic will be passed by value.