Some object x is a chair if and only if$...$x can be sat on$.$x has four legs.x has a backrest.To show that this definition fails for chair, one needs an example of$....$Group of answer choicesAn object that has a backrest but is not a chair.An object that can be sat on but is not a chair.An object that is a chair but does not have four legs.An object is cannot be sat on and is not a chair.