The pairs of rectangular co-ordinate planes have equations
xy=yz=0
x=y=z
xyz=0
None of these
Explanation for the correct option
We know that the pair of rectangular co-ordinate planes have the equations
xy=yz=zx=0
So, xy=yz=0
Hence, option A is the correct answer.
The equation of the sphere touching the three co-ordinate planes is [AMU 2002]