ANS:A - increases.

In a distillation column, with an increase in the reflux ratio:

• The heat removed in the cooler increases.
• The reflux ratio represents the ratio of the liquid reflux returned to the column to the distillate withdrawn from the column. Increasing the reflux ratio means more liquid reflux is returned to the column, which increases the amount of condensation in the condenser. As a result, more heat is removed from the vapor phase in the condenser, leading to an increase in the heat removed in the cooler.
• The heat required in the reboiler increases.
• The reboiler is responsible for providing the heat necessary to vaporize the liquid in the bottom of the column. With an increase in reflux ratio, more liquid is returned to the column, resulting in a higher liquid flow rate at the bottom of the column. This increased liquid flow requires more heat input in the reboiler to maintain vaporization and separation efficiency.