In this task, you are given a multiple-choice question and you have to pick the correct option. Answer with option indexes (i.e., "A", "B", "C", and "D").

Example Input: Using mirrors to focus collected light from heavenly bodies allows (A) detailed observation (B) foregone conclusions (C) radiation experiments (D) celestial music
Example Output: A

Example Input: A person who wants to eat a watermelon may consider spitting out its (A) dark pips (B) good taste (C) coco pebbles (D) red fruit
Example Output: A

Example Input: Imagine astronauts traveling to a distant asteroid as it passes near Earth. During their mission they leave behind boot prints. How long will these potentially last? (A) several months (B) 5 years (C) thousands of years (D) 2 weeks
Example Output:
C