Auniformed law enforcement officer working in the terminal building of an airline airport, outside the secured area, notices two men who appear middle eastern entering a crowded airport restaurant. both are carrying suitcases. as they pass close by him, they are conversing softly but excitedly in a language he thinks might be arabic. they do not make eye contact with him. can the officer legally: a. stop the pair and question them? explain. b. frisk them for weapons? explain. c. search their bags for explosives? explain.