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").

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


[Q]: If you fly from Europe to Australia in December, when you arrive you will most likely want to wear: (A) heavy coat (B) mittens (C) shorts (D) ski mask
[A]: C


[Q]: How many phases are present in a closed flask if it contains ice, water and air (A) 5 (B) 3 (C) 2 (D) 6
[A]:
B