Relative humidity is
a) the actual mass of moisture present in a specific amount of air
b) the ratio of the mass of moisture contained in a specific amount of air to the maximum amount of moisture this specific amount of air can contain
c) the maximum mass of moisture that a specific amount of air can contain
d) the ratio of the mass of air contained in a specific amount of moisture to the maximum amount of air this specific amount of moisture can contain
e) a specific amount of air saturated with moisture
Answer: B