When is a static variable inside a function initialized?

A static variable inside a function is only initialized the first time the function is invoked, meaning it will retain its value even after the function has completed. Option A is incorrect because a static variable declared inside a function will not be initialized every time the function is called. Option C is incorrect because a static variable will not be initialized when the program ends, it will retain its last assigned value. Option D is incorrect because while a static variable is not automatically initialized, it can be manually initialized in the function. Therefore, option B is the correct answer.