In one interview I was asked, if in one file A, some static function is defined and in file B you want to use this static function -- how you will use it?

My answers were: 

1. declaring in .h file
But if we declare that in a header file, other files which will include this also have access to this static function.
2. wrapper concept: Declaring a new function `newfun` in file A, which will call static function and calling this `newfun` in file B.

But he was not satisfied with these answers.

Can you please provide me some better solution to violate `static`.