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").

Input: Consider Input: heat and pressure change the remains of what into natural gas? (A) leaves (B) cans (C) books (D) cars

Output: A

Input: Consider Input: An object converts electrical energy into sound on a (A) iphone (B) soft carpet (C) outside wall (D) wooden table

Output: A

Input: Consider Input: Droughts can cause (A) parched grass (B) lush lawns (C) overflowing ponds (D) blooming flowers
Output: A