The equation of the x y-plane is: (a) x=0, y=0 (b) z=0 (c) x=0, y \neq 0 (d) None of these
The equation of the x y-plane is: (a) x=0, y=0 (b) z=0 (c) x=0, y \neq 0 (d) None of these

SOL:
Correct option is B. z=0