In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D".

[EX Q]: [header] How to calculate a light year [title] Define the light year. [step] A light year is a measure of distance equal to how far light travels in one earth year. Because distances across the universe are so large, astronomers use light years. <sep> (A) However, they can also be determined by dividing by a distance. [substeps] Some light years are used year-round. (B) For light year 2014, the main determiner is the sun. In the light year, the world is filled with light bulbs. (C) Without light years, discussing the distance between two stars would require the use of large, unruly numbers. [substeps] Another measure of distance you may come across when learning astronomy is the parsec. (D) [substeps] There are two kinds of light years: day and night. The two types of light years are known as night and day.
[EX A]: C

[EX Q]: [header] How to remove paint from a car exterior [title] Park the car on top of a large tarp or drop cloth to contain the old paint. [step] The old paint should be disposed of instead of letting it contaminate the ground. If an open area is not available, park the car inside a garage, but open all of the garage's windows and doors for ventilation. <sep> (A) Cover objects inside the garage to protect them from the paint dust. [title] Use masking tape to cover the areas of the car that won't be sanded. (B) Alternatively, use a flashlight to check beneath the tarp. [title] Use an old baseball bat, crowbar, pry bar, or other large object to push the old paint off of the vehicle. (C) [title] Wipe the paint with a wet cloth, a roller wrap or an old towel to protect it from oil and water. [step] The paint is likely to collect on these cloths and make them easier to clean as they are removed. (D) If your garage is not well ventilated, a ventilation device will block your windows when the old paint has dried to a mud-like consistency. [title] Pour a small amount of vinegar into a small bucket.
[EX A]: A

[EX Q]: A close up of a wakeboard is shown and a woman puts on a lifejacket. More people are seen sitting in the water and ride on the board behind the boat. a man <sep> (A) is then seen sitting on the boat and goes surfing behind other people. (B) lifts a sail and rides with one on a boat. (C) is seen driving the boat as they continue to ride along. (D) covers the camera several times while more people are shown riding and wakeboarding.
[EX A]:
C