ii. In a multi-source program, there is a fileA.c that contains variables and functions, and a fileB.c that contains the main function, as well as usage of some of the resources found in fileA.c. Explain: a) fileA.c has a global variable called my_variable, that should only be accessed within the file. I.e., no other files should be able to access that variable. How should my_variable be declared inside of the file, in order to guarantee this functionality