200 kmol/h of a liquid mixture of light alcohols containing, by moles, 50% ethanol (E), 35% isopropanol (IP), and 15% normal propanol (NP) is distilled in a sequence of two distillation columns. 80% of E is recovered in the distillate from the first column and the bottoms from the first column is fed to the second column. The recovery of IP from the bottom product of the first column is 80% in the distillate of the second column. The purity of IP in the bottoms from the second column is 28%. Assume no propanols in the distillate from the first column, no normal propanol in the distillate from the second column. Calculate the purity of ethanol in distillate product of the second column. A)12 B)20 C)50 D)56 E)70