Question

Consider the following treatments:       

        1. Normalizing

         2. Hardening

         3. Martempering

         4. Cold working              

         Hardness and tensile strength in austenitic stainless steel can be increased by

         (a) 1, 2 and 3                  (b) 1 and 3

         (c) 2 and 4                      (d) 4 alone