Find the points of discontinuity of $y=\large\frac{1}{u^2+u-2}$ where $u=\large\frac{1}{x-1}$

Question

$(a)\;1,-1\qquad(b)\;\large\frac{1}{2}$$,0\qquad(c)\;0,1\qquad(d)\;\large\frac{1}{2}$$,1,2$