If z=x+iyz = x+iyz=x+iy, which expression represents ∣z2∣|z^2|∣z2∣?
x2+y2x^2+y^2x2+y2
x4−y4x^4-y^4x4−y4
(x2+y2)2(x^2+y^2)^2(x2+y2)2
x2−y2x^2-y^2x2−y2