ANS:D - toughness & transverse ductility.

Presence of sulfur in steel can have detrimental effects on its mechanical properties. One of the significant impacts is on toughness and transverse ductility. Sulfur can lead to the formation of sulfide inclusions in steel, which act as stress concentration sites and reduce the ductility and toughness of the material. These inclusions can promote premature failure, particularly under conditions of dynamic loading or impact. Therefore, the correct option is:

• toughness & transverse ductility.