Why is a macro used in place of a function? ans. It reduces code size. It increases execution time. It increases code size. It reduces execution time.

A macro is used in place of a function for several reasons:

1. It reduces code size: Macros are preprocessed by the preprocessor in C/C++ programming languages. This means that the macro code is expanded at compile time, which can lead to a reduction in the overall size of the code.

2. It increases execution time: Since macros are expanded at compile time, there is no overhead of function calling, which can lead to faster execution of the program.

3. It increases code size: This point seems contradictory to the first point. While the use of macros can reduce the overall size of the code, the expanded macro code can sometimes lead to an increase in the size of the compiled program.

4. It reduces execution time: As mentioned earlier, since macros are expanded at compile time, there is no overhead of function calling. This can lead to a reduction in the execution time of the program.

So, the use of macros can lead to both an increase and decrease in code size, depending on the situation. However, the main advantage of using macros over functions is the potential for faster execution time.