A.f:x→x2-x+1 B.f:x→x+(x-1)2
C.f:x→2x-1-1 D.f:x→2x-1
解析:由映射概念知f:x→2x-1是从A={1,2,3,4,5}到B={1,3,7,15,31,33}的映射,故选D.
答案:D.