Answer: Option B
:
B
A point source radiates energy equally in all direction


Same is true for a spherical source. Assuming it radiates energy equally in all directions

An infinite line source will radiate energy perpendicular to its surface in all direction. So the wave front will be…

Yup......Right again.
Cylindrical.

Plane source.

Planar light source will have planar wave fronts.
So correct answer is infinite line source will have a cylindrical wave front.