Which of the following statement(s) about global variables is(are) true?
A) If a function contains a local variable with the same name as a global variable, the global variable's name takes precedence within the function. B) A global variable can have the same name as a variable that is declared locally within a function C) A global variable is the same as a named constant. D) A global variable is declared in the highest level block in which it is used. E) A global variable is accessible only to the main function.