To answer this question, you need to understand the concept of static methods in object-oriented programming.
Option A) function - This option is incorrect because the keyword "function" is a general term used to define a block of reusable code, but it does not specifically indicate a method that can be used without instantiating a class.
Option B) static - This option is incorrect because the keyword "static" is used to define variables or methods that belong to a class itself, rather than to instances of the class. However, it does not specify whether the method can be used without instantiation.
Option C) static function - This option is correct because the combination of the keywords "static" and "function" indicates a method that can be accessed and used without instantiating the class to which it belongs. It is a method that belongs to the class itself and can be called directly.
Option D) public function - This option is incorrect because the keyword "public" is used to define the visibility of a method (i.e., whether it can be accessed from outside the class), but it does not specify whether the method can be used without instantiation.
The correct answer is C) static function. This option is correct because it specifically indicates a method that can be used without instantiating the class.