Correct Option - D

ExplanationVariable names in C are made up of letters (upper and lower case) and digits. The underscore character ("_") is also permitted. Names must not begin with a digit. Examples of valid (but not very descriptive) C variable names: => foo => Bar => BAZ => foo_bar => _foo42 => _ => QuUx

Correct Option - C

Explanationfmod(x,y) - Calculates x modulo y, the remainder of x/y. This function is the same as the modulus operator. But fmod() performs floating point divisions.

Correct Option - A

Explanation

Correct Option - B

Explanation

External Linkage-> means global, non-static variables and functions.

Internal Linkage-> means static variables and functions with file scope.

None Linkage-> means Local variables.

Correct Option - A

Explanation

/* Example for ceil() and floor() functions: */

#include
#include

int main()
{
    printf("\n Result : %f" , ceil(1.44) );
    printf("\n Result : %f" , ceil(1.66) );
 
    printf("\n Result : %f" , floor(1.44) );    
    printf("\n Result : %f" , floor(1.66) );

    return 0;
}
// Output:
// Result : 2.000000
// Result : 2.000000
// Result : 1.000000
// Result : 1.000000

Correct Option - B

Explanation

A function prototype in C or C++ is a declaration of a function that omits the function body but does specify the function's name, argument types and return type.

While a function definition specifies what a function does, a function prototype can be thought of as specifying its interface.

Correct Option - C

Explanation

fmod(x,y) - Calculates x modulo y, the remainder of x/y.

This function is the same as the modulus operator. But fmod() performs floating point divisions.