Answer:
A. The ash would increase the albedo and decrease the global temperature
Explanation:
The volcanoes can have a big impact on the global temperature. If the volcanic eruption is big enough, and the volcanoes manages to propel very large amount of ash in the atmosphere, the whole planet will feel the effect. The ash will make a layer in the atmosphere around the planet. This layer will increase the albedo of the atmosphere, as the ash will block big portion of the sunlight. That will result in much less sunlight reaching the surface of the Earth, thus in sharp decrease in the global temperatures.