If a+1/a=1 than (1+a-a²)×(1-a+a²)=?

Question

(a)1

(b)2

(c)3

(d)4

Answer 1

a +1/a =1 Since a not equal to zero the expression simplifies to a^2 + 1 = a that is

a^2 +1 - a = 0 Therefore answer is (1 + a - a^2) (1- a +a^2) = 0 none of the options given.