5. The specific heats of iodine vapor and solid are 0.031 and 0.055 cal/g, respectively. If the enthalpy of sublimation of iodine is 24.0 calg at 200℃, the enthalpy of sublimation of iodine at 250℃should be (A) 24.0 cal/g, (B) 26.4 cal/g, (C) 20.8 cal/g, (D) 28.6 cal/g, (E) 22.8 cailg.