Given expression is x(a - c) + y(c - a).
Rearranging this expression, we get:
x(a - c) - y(a - c)
We can factorize (a - c) from both terms to get:
(a - c)(x - y)
Therefore, the factorization of the expression x(a - c) + y(c - a) is (a - c)(x - y).
The correct option is (b) (a - c)(x - y).