Two 10 cm long aluminium rods and five 8 cm long steel rods are at 5°C temperature and are joined together to form a 60 cm long rod. What is the increase in the length of the joined rod when the temperature is raised at 80°C? (Use a coefficient of linear expansion for aluminium= \( 2.4 × 10^{- 5} K^{- 1} \) and coefficient of linear expansion for Steel \( = 1.2 × 10^{- 5} K^{- 1} ) \)

A 0.3 mm

B 0.5 mm

C 1.8 mm