某村农民张某被害,有四个嫌疑犯 A,B,C,D 。公安局派出五个侦察员,他们的侦察结果分别是: A , B 之中至少有一人作案, B , C 中至少有一人作案, C , D 中至少有一人作案, A , C 中至少有一人与此案无关, B , D 中至少有一人与此案无关,所有侦察结果都是可靠的。请用归结原理求出谁是罪犯?
【简答题】A.Get grade A in each year. B.School results are good each year. C.Three out of four subjects are passed. D.The study time lasts more than five years.