Q1: Is it true that a function may have several declarations, but only one definition?

ANS:A - Yes

Yes, but the function declarations must be identical. Example:

#include<stdio.h>

void Display();
void Display();
void Display();

void Display()
{
   printf("Weclome to AptitudeCrack.com..!");
}

int main()
{
    Display();
    return 0;
}

//Output:
Weclome to AptitudeCrack.com..!