Which statement describes the effect of passing by value versus passing by reference on the caller's data?

• A. Passing by value copies data; passing by reference allows the function to modify the original data.
• B. Passing by value allows modification of the original data; passing by reference copies the data.
• C. Both pass by value copies data; by reference does not modify data.
• D. By value does not copy data; by reference copies data.

Answer: (A)