已知$f\left(x\right)$为偶函数，当$x\ge 0$时，$f\left(x\right)=\left\{\begin{array}{l}\cos \pi x,x\in [0,\frac{1}{2}]\\ 2x-1,x\in (\frac{1}{2},+\infty )\end{array}\right.$，则不等式$f(x-1)\le \frac{1}{2}$的解集为（）

A．	$[\frac{1}{4},\frac{2}{3}]\cup [\frac{4}{3},\frac{7}{4}]$	B．	$[-\frac{3}{4},-\frac{1}{3}]\cup [\frac{1}{4},\frac{2}{3}]$
C．	$[\frac{1}{3},\frac{3}{4}]\cup [\frac{4}{3},\frac{7}{4}]$	D．	$[-\frac{3}{4},-\frac{1}{3}]\cup [\frac{1}{3},\frac{3}{4}]$