Hello from MrBillDoesMath!
Answer:
Choice B
Discussion:
In the original statement, x^4 - 4x^2 +4, note x^4 is the square of x^2 suggesting that if we set u = x^2 the original equation is equivalent to
u^2 -4u + 4
which factors as
(u -2)^2
Since u = x^2, the final factorization is
(x^2 -2) ^2
This is Choice B
Thank you,
MrB
