You will be given a definition of a task first, then some input of the task.
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").

Shivering is when an animal creates heat by shaking to keep the body what? (A) frozen (B) freezing (C) cold (D) agreeable temperature
Output:
D