The correct option is B Hollow circular
For a given amount of torsional moment, the section which develops least value of τmax (maximum shear stress) will be best.
Jsolidcircular < Jhollowcircular
(Considering same weight of solid & hollow sections)
τsolidcircular < τhollowcircular
Also, square, rectangular, triangular and other polygonal sections have sharp edges or fillets which reduce surface area, thus increasing the stress in those places. Hence, they are not very effective in resisting stress against the torque.
∴ Hollow circular section will be best in torsion.