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". 

Example Input: A view is seen of the outside of an airport, then the wing of the flying plane. A man is on the plane wearing a mask. several people <sep> (A) are sleeping in the dark quarters. (B) fly by on a road inside the plane. (C) are shown flying the aircraft, while shooting at a large target at one point. (D) speak, then they all fly kites on the plane while people walk by.
Example Output: A

Example Input: A man wearing grey shorts kneels down on a carpeted floor and begins stretching. The man moves his right leg under his hip and in front of his left knee. the man <sep> (A) continues exercising his left leg. (B) is then sitting while he's exercising and putting a harness. (C) then begins looking comfortable about doing this and stretches. (D) begins to rock back and forth in a slow movement as he stretches.
Example Output: D

Example Input: [header] How to identify canine flea problems [title] Look for behavioral signs of a flea infection. [step] Is your dog scratching itself more than usual? Is it gnawing at its coat? These are signs that your dog might have fleas. [substeps] Flea bites can cause itchiness on the dog's skin. <sep> (A) Flea bites can also appear as other symptoms of fleas, such as a rash. You may see different white patterns appear on your dog's skin, such as irregularities on the legs. (B) The bites can make small red bumps on the skin and continue to itch for some time. Some animals can actually be allergic to these bites, making the itching and redness more intense and widespread. (C) There may be substantial accumulating beard hairs, brown hair, or quills. Even fleas that come from dog's fur may cause itching that leads to cushing's disease. (D) These sores are believed to be caused by fleas. White pus-filled sores, discolored gums, itchy or red spots may appear after scratching.
Example Output:
B