题目（2023九上·高台开学考）下列分式中是最简分式的是（ ）A.2xx+1\frac { 2x } { x+1 }x+12xB.26x\frac { 2 } { 6x }6x2C.x−1x2−1\frac { x-1 } { x ^ { 2 } -1 }x2−1x−1D.1−xx−1\frac { 1-x } { x-1 }x−11−x知识点：最简分式章节：未标注
