The correct option is C Greenhouse effect
A. Though no one is unaware of the
B. Greenhouse effect
C. no one does anything to stop air pollution.
Thus Option C is correct because Greenhouse gases is related to air pollution.
A greenhouse gas is any gaseous compound in the atmosphere that is capable of absorbing infrared radiation, thereby trapping and holding heat in the atmosphere. By increasing the heat in the atmosphere, greenhouse gases are responsible for the greenhouse effect, which ultimately leads to global warming.