Hot rolling of mild steel is carried out

1. at recrystallization temperature
2. between 100°C to 150°C
3. below recrystallization temperature
4. above recrystallization temperature

Hot working is carried out at above Recrystallization temperature.
Hot working > 0.6 T_m
and Recrystallization Temp = 0.5 T_m
T_m = melting point.