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: Digestion is when stomach acid breaks down what? (A) food essays (B) sustenance (C) water (D) air

Output: B


Input: Consider Input: Humans contribute to environmental pollution (A) by purchasing products made from recycled products (B) by switching to energy efficient appliances (C) by leaving behind refuse on public beaches (D) by frequently recycling paper and plastic

Output: C


Input: Consider Input: Dirt is moved from one part of a forest to another, and travels across a field to get there. The movement is (A) caused by gusts (B) due to clouds (C) made by trees (D) because of litter


Output: A