Answer: Option (b) is the correct answer.
Step-by-step explanation:
Humidity means the amount of water present in the air. Whereas relative humidity means amount of vapour present in the air compared to the amount of vapour it can hold for saturation at that temperature.
Warmer air requires more moisture in order to become saturated as compared to colder air. When water vapour content remains the same and temperature decreases then their will increase in relative humidity. As a result, humidity will also increase.
Whereas when water vapour content remains the same and temperature increases then their will be decrease in realtive humidity. As a result, humidity will also decrease.
Hence, we can conclude that as the amount of water vapor in the air increases, the relative humidity increases.