State the possible number of positive and negative roots for the equation x^6 - x^4 - x^2 + 1 - 0

A) Possible # positive real roots: 3 or 1
Possible #negative real roots: 2 or 0

B) Possible #positive real roots: 4
Possible # negative real roots: 2 or 0

C) Possible #positive real roots: 2 or 0
Possible #negative real roots: 2 or 0

D) Possible # positive real roots: 4,2, or 0
Possible #negative real roots: 2