Answer:
D. all of the above
Step-by-step explanation:
A option is correct and function definition must be written before they are called by another part of your program. But in languages such as C++ you can write the prototype of the function before it is called anywhere in the program and later write the complete function implementation. I will give an example in Python:
def addition(a,b): #this is the definition of function addition
c = a + b
return c
print(addition(1,3)) #this is where the function is called
B option is correct and function definition must declare a name for the function. If you see the above given function, its name is declared as addition
C option is correct and function definition must include information regarding any arguments (if any) that will be passed to the function. In the above given example the arguments are a and b. If we define the above function in C++ it becomes: int addition( int a, int b)
This gives information that the two variables a and b that are parameters of the function addition are of type int so they can hold integer values only.
Hence option D is the correct answer. All of the above options are correct.