The Enriching section operating line intercept at the origin in McCabe-Thiele method when
The Enriching section operating line intercept at the origin in McCabe-Thiele method when Correct Answer Reflux ratio= Infinity
When the Enriching section operating line intercept at origin then the operating line will become the diagonal line (45 degree line) that means all the condenser product are refluxed( No distillate). i.e. Reflux ratio =(R/D) if D=0 then reflux ratio tends to infinity that gives a minimum number of trays for designing the distillation column.