Water Vapor Is a Greenhouse Gas and Has Higher Concentrations

Water vapor is a greenhouse gas and has higher concentrations in the atmosphere than CO₂.Why then is CO₂ considered to be the primary greenhouse gas?

A) Water vapor has a much longer residence time in the atmosphere than CO₂.
B) Additions of CO₂ decrease the amount of water vapor the atmosphere can hold which amplifies warming.
C) Additions of CO₂ increase the amount of water vapor the atmosphere can hold which amplifies warming.
D) Lower levels of water vapor drive increases in CO₂ concentrations.
E) Water vapor concentrations are decreasing while CO₂ concentrations rise.