The correct option is D increases with the increase in stirrup and longitudinal steels
(d) The amount of torsion in a member depends upon the magnitude of the torsional stiffness of the member itself in relation to the stiffness of the interconnecting members. In reinforced concrete structures, the stiffness decreases considerably after the formation of cracks if the continuity at the joint are not considered in the design. The presence of reinforcement in the form of longitudinal and transverse steel increases the torsional moment carrying capacity of beams·.