ANS:B - Tempering

The process that follows the hardening process for reducing the hardening strains and increasing the toughness of the steel part is tempering. Tempering is a heat treatment process that involves heating the hardened steel to a specific temperature below its lower critical point and then cooling it down, usually in still air. This process helps to relieve internal stresses and reduces the hardness of the steel, making it tougher and more ductile while retaining some of its strength.