What will be the output of the following C code?

#include <stdio.h>
#define p( n,m ) printf( "%d", m##n )
#define q(a,b) printf("%d",a##b)
main()
{
   p(3,4);
   q(5,6);
}

A. Compile C code B. Optimize code C. Preprocess code before compilation D. Execute code

A. #define B. #include C. #ifdef D. #pragma

A. To include a header file B. To define a macro C. To declare a constant D. To declare a variable

A. #ifdef B. #ifndef C. #if D. #else