A solid object of mass M is made of material of specific heat capacity c, latent heat of fusion L and of very high thermal conductivity. When the object enters the atmosphere from outer space, its temperature below its melting point by \[\Delta T\]. Because of atmospheric friction, it absorbs energy at a constant rate of R. The time before the solid becomes completely molten is

• A. \[\frac{M(C+L)\Delta T}{R}\]
• B. \[\frac{M(C\Delta T+L)}{R}\]
• C. \[\frac{M(C+L)\Delta T}{R}\]
• D. \[\frac{R}{(M\Delta T(C+L)}\]