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").

Ex Input:
Fact1: Carbon may be stored in sedimentary rock for millions of years., Fact2: Limestone is a type of sedimentary rock., Question: What element can be stored in limestone for millions of years? (A) oxygen (B) Energy (C) matter (D) carbon (E) sodium (F) helium (G) rock salt (H) heat

Ex Output:
D


Ex Input:
Fact1: Aging occurs as cells lose their ability to divide., Fact2: Death is attributed to the infirmities of old age., Question: What occurs as cells lose their ability to divide? (A) illness (B) Winter (C) disease (D) death (E) youth (F) die (G) black holes (H) cell growth

Ex Output:
D


Ex Input:
Fact1: acid rain has a negative impact on water quality, Fact2: Cars and trucks emit tremendous amounts of airborne pollutants, which increase acid rain., Question: Which of the following has the worst effect on water quality? (A) bacteria (B) Pesticides (C) fossil fuels (D) deforestation (E) cars and trucks (F) humans disturb it (G) flooding (H) Destroy bridges

Ex Output:

E