Correct Answer - D
`(d)` Magnetic induction at `(a,0,a)` due to loop in `xy` plane is in `+k` direction. Due to loop in `yz` plane, the magnetic field will be in `(+hat(i))` direction. Due to both the loops, the direction of `vec(B)` will be `(1)/(sqrt(2))(hat(i)+hat(k))`