The Temperatures in a Fractionating Tower at an Oil Refinery

The temperatures in a fractionating tower at an oil refinery are important,but so are the pressures.Where might the pressure in a fractional distillation tower be greatest,at the bottom or at the top? Defend your answer.

A) The pressure is greatest at the bottom because the higher temperature means a greater number of vaporized molecules.
B) The pressure is greatest at the top because the higher temperature means a greater number of vaporized molecules.
C) The pressure is greatest at the bottom because the lower temperature means a greater number of vaporized molecules.
D) The pressure is greatest at the top because the lower temperature means a greater number of vaporized molecules.