Three infinitely long wires with linear charge density are placed along the x-axis, y-axis and z axis respectively

Three infinitely long wires with linear charge density λ are placed along the x-axis, y-axis and z axis respectively. Which of the following denotes an equipotential surface ? 

(1) xy + yz + zx = constant

(2) (x + y) (y + z) (z + x) = constant

(3) (x2 + y2 ) (y2 + z2 ) (z2 + x2 ) = constant

(4) xyz = constant

 (JEE-2025)