In a fraud case, Zhao and Li were targeted after investigation. Both Zhao and Li may be scammers or eyewitnesses. Known scammers only tell lies and witnesses only tell the truth. Interrogators Ask Zhao: "Surely one of you two is a witness?" Zhao answered: "No. ". What are Zhao and Li? ['Zhao is a witness and Lee is a scammer.', 'Zhao and Li are both witnesses.', 'Zhao is a scammer and Lee is a witness.', 'Zhao and Li are both scammers.']