[单选题]
Supersaturation occurs tqb z-m u*5a+oi4 xmr9h(,cbl s:.idwcn air when the
A. relative humidity is 100% and the temperature increases.
B. relative humidity is less than 100% and the temperature increases.
C. relative humidity is less 100% and the temperature decreases.
D. relative humidity is 100% and the temperature decreases.
