What's the greenhouse effect?

a. the release of extra moisture from water vapor
b. human-caused global warming
c. the regulation of atmospheric and surface temperatures
d. the trapping of warm air in cities

do yall know the answer?

well first you need the sample of the temperature and gas level. i couldnt write a hypothesis unless i had some data. i think temperature changes will effect volumes of gas because gas changed into a solid or liquid at specific temperatures.