Consider the given expression,
x(ax−1)(a−x+1)
Replace x by –x , we get,
=−x(a−x−1)(a−(−x)+1)$
=−x(1ax−1)(1ax+1)=x(1−axax)(1+axax)
=−x(1−ax)1+ax=−x(−(−1+ax))1+ax
=x(ax−1)1+ax
=x(ax−1)(a−x+1) is the even function.
Option (c) is correct answer