Correct option is A
During normalising of low-carbon steel, the steel is heated above its critical temperature and then cooled in air. This results in a fine-grained microstructure consisting of ferrite and pearlite. Ferrite provides ductility, while pearlite contributes to strength and hardness. This balanced structure improves mechanical properties compared to annealed steel.
Other structures like austenite exist only at high temperatures, while bainite and martensite form under different cooling conditions (faster cooling).
