A function is executed when it is

A.

defined

B.

prototyped

C.

declared

D.

called

D. called

Explanation:

A function is executed when it is called.

Function definition comprises of the code body of the function. For example:

int add (int a, int b) {

return a+b;

}

Function declaration or function prototype specifies the signature of the function (number and type of arguments, return type). e. g,

int add (int a, int b);

Function call is when the function is executed with actual arguments:

add (2,4);

This will return 6 upon execution of function body.