A rectangular ice box of total surface area of $1000 \mathrm{~cm}^2$ initially contains 1.5 kg of ice at $0{ }^{\circ} \mathrm{C}$. If the thickness of the walls of the box is 2 mm and the temperature outside the box is $42^{\circ} \mathrm{C}$, then the mass of the ice remaining in the box after 160 minutes is (Thermal conductivity of the material of the box $=10^{-2} \mathrm{Wm}^{-1} \mathrm{~K}^{-1}$ and latent heat of the fusion of ice $=336 \times 10^3 \mathrm{Jkg}^{-1}$ )

• A

  0.6 kg
• Correct answer
  B

  0.9 kg
• C

  0.8 kg
• D

  0.7 kg

Hence, the correct answer is option: 'B'.