Which of the following is false?

a. When you pass a variable by reference, the receiving function can change the variable’s contents.

b. When you pass a variable by value, the receiving function creates a local variable that it uses to store the value.

c. Unless specified otherwise, all variables in C++ are passed by value.

d. To pass a variable by reference in C++, you place an ampersand (&) before the variable’s name in the statement that calls the function.