WBJEE 2025 Math Paper

Symmetric form
‌

x−3

3

=‌

y−2

1

=‌

z−1

0

=t
Equivalently,
(x,y,z)=(3,2,1)+t(3,1,0)
So its direction vector is
d=(3,1,0).
Compare with the z-axis direction vector k=(0,0,1) :
d⋅k=3⋅0+1⋅0+0⋅1=0.
A zero dot product means the two lines are perpendicular.
Since it's neither purely along x nor y, but its direction is orthogonal to the z-axis, the correct choice is