A 100 kmol/hr feed containing an equimolar A (lighter) and B (heavier) is to be rectified in a continuous tray column operating at atmospheric pressure. The distillate vapor line is 50 kmol/hr containing 50% mol% A and the bottom liquid product line is 50 kmol/hr containing 5% mol% A. The equation of the operating lines are: Top operating line: y = 0.868x + 0.12; Feed line: y = 7x - 3. The ratio of the liquid flow rate to the vapor flow rate in the stripping section is: Select one: a. 1.428 b. 1.379 c. 1.126 d. 1.324