As Hygroscopic Aerosol Particles Enter the Respiratory Tract, What Do

As hygroscopic aerosol particles enter the respiratory tract, what do they tend to do?

A) Decrease in size because of the absorption of molecular water.
B) Increase in size because of the absorption of molecular water.
C) Increase in size because of the evaporation of molecular water.
D) Decrease in size because of the evaporation of molecular water.