You are given a science question (hard-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

Ex Input:
How does a parachute sufficiently increase air resistance to allow the parachutist to land safely?   
 (A) by decreasing the force of gravity acting on the parachutist (B) by decreasing the total mass of the parachutist (C) by increasing the surrounding air pressure around the parachute (D) by increasing the total surface area of the parachute

Ex Output:
D


Ex Input:
An astronomer observes that a planet rotates faster after a meteorite impact. Which is the most likely effect of this increase in rotation?  
 (A) Planetary density will decrease. (B) Planetary years will become longer. (C) Planetary days will become shorter. (D) Planetary gravity will become stronger.

Ex Output:
C


Ex Input:
Two identical sheets of paper are used in an experiment; one is crumpled into a ball and the other is flat. What will most likely happen when they are dropped at the same time from the same height?  
 (A) flat sheet will fall on its edge (B) both will fall at the same rate (C) crumpled sheet will fall faster (D) crumpled sheet will move horizontally

Ex Output:

C