Question: Both `self` and `this` are keywords that can be used to refer to member variables of an enclosing class. The difference is that `$this->member` should be used for ** members and `self::$member` should be used for ** members.
- private, public
- object,primitive
- non-static,static
- concrete,abstract
Answer: The correct answer of the above question is Option C:non-static,static