'Pigeonhole' is a term used for one of a series of small compartments for papers or letters. This reasoning marks option (1) correct. The word pigeon-toed as used in option (2) refers to condition of body in which person's toes are turned inwards. As used in option (3), pigeonholed implies postponed. As given earlier, pigeon-toed can't be used to refer to non-physical attribute. This implies option (4) as required answer choice.