Which of the following best explains why the boiling point of water decreases at higher altitudes?
A) The increased atmospheric pressure at higher altitudes causes water molecules to boil at a lower temperature.
B) The reduced atmospheric pressure at higher altitudes allows water molecules to escape into the gas phase at a lower temperature.
C) The increased atmospheric pressure at higher altitudes forces water molecules to remain in the liquid phase longer.
D) The reduced atmospheric pressure at higher altitudes increases the temperature required for water molecules to boil.