Detailed Instructions: In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").
Q: Fact1: volcanic ash in the atmosphere decreases the temperature by blocking the sun, Fact2: Most volcanic ash consists of fine, dusty particles., Question: How do fine, dusty particles in the atmosphere erupted from volcanoes lower the temperature? (A) occurs over a wide range (B) drastically (C) calibrated (D) by blocking the sun (E) how they move (F) a surface not sterilized (G) oxygen spreads into the air (H) feedback mechanisms
A:
D