Q1: Functions cannot return a floating point number

ANS:B - No

A function can return floating point value. Example:

#include <stdio.h>
float sub(float, float); /* Function prototype */

int main()
{
    float a = 4.5, b = 3.2, c;
    c = sub(a, b);
    printf("c = %f\n", c);
    return 0;
}
float sub(float a, float b)
{
   return (a - b);
}

Output:
c = 1.300000