The eruption of mt. pinatubo in the philippines a) caught the human population unaware, giving no prior signs of activity. b) affected only local, island ecosystems. c) produced aerosols that blocked the sun and resulted in a drop in global temperatures. d) produced large amounts of sulfur dioxide but few aerosols.

Correct C
A) Before the actual first eruption on June 3, 1991, since early March, several other happenings occur such as earthquakes, phreatic eruptions, releasing of ashes, etc. that made the population aware of what was about to happen.
B) It affected the whole atmosphere and consequently the whole earth, having had effects throughout the whole world climate, agriculture, health, and other parameters.
D) It produced so many aerosols that's thought to be the largest eruption at emitting aerosols since Krakatoa's eruption.