Answer:
The correct answer would be the haze effect.
The haze refers to the atmospheric phenomenon in which fine particles suspended in the atmosphere such as smoke, dust, soot, ash et cetera obscure the sky clarity.
Volcanic eruptions emit a huge amount of mixture of gases and fine particles such as sulfur dioxide and ash. Clouds of these particles reach high in the troposphere as well as stratosphere and block or reduce the number of solar radiations reaching the earth. It reduces the average global temperature.
In addition, the sulfurous gases react with water to form acidic aerosols in the atmosphere. These aerosols absorb and reflect the solar radiations back into space.