The scope of a variable declared outside of any function is:
a) global
b) local
c) within that file only

a) Global

Explanation:

The scope of a variable declared outside of any function is Global.

Let us consider an example:

int g;

int  add(int a,int b){

   return a+b;

}

int  subtract(int a,int b){

   return a-b;

}

Here the variable g is defined outside any function and is accessible anywhere within the program. This is a global variable.

Variables defined within each function - a,b on the other hand have a local scope are are visible only within their respective function bodies.