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: [header] How to fall asleep if you are blind or visually impaired [title] Talk to your doctor. [step] If you are a blind or visually impaired person who is having trouble falling asleep, you should set up an appointment with your doctor. Ask your doctor to examine you for non-24, a sleep disorder that frequently affects visually impaired and blind people. <sep> (A) This can help you make a diagnosis and develop strategies to speed up your recovery. [substeps] Ask your doctor if sleep loss, depression, dyslexia, or dyslexia problems might be the issue and advice you need. (B) A doctor can make a diagnosis of a sleep disorder and understand your problem. Treatment of the sleep disorder based on the condition will help your doctor identify the underlying cause and decide how long it is necessary to treat you. (C) Your doctor may refer you to an optometrist or psychologist who has experience treating dementia or cognitive dysfunction. Your doctor may want to examine you in several places or diagnose various medical conditions. (D) [substeps] Non-24 is a disorder that affects your sleep-wake cycles and is common in blind people. People with non-24 have trouble falling and staying asleep at night, as well as extreme urges to nap during the day.
Example Output: D

Example Input: [header] How to put music on facebook [title] Navigate to the website that features the music you want shared. [step] Examples of such websites are youtube and soundcloud. [title] Click on the " share " button located next to the music selection you want shared. <sep> (A) [step] You will be redirected to a page explaining to you exactly what music you want shared, and the category where it can be shared. [title] Click on " share " located below " share " in the drop-down menu. (B) [step] If you have multiple fans or listeners, you may see a link in the sidebar that says, " add a facebook friend to your friends list ". Click it if you want to add a facebook friend in the list. (C) [title] Scroll down until you see the right size. [step] If you are looking for music that is already on facebook, such as songs from a specific artist and/or a series of popular music videos, you will see the appropriate size. (D) [title] Select the option for facebook when asked how you want to share your selection. [title] Enter your facebook login information at the prompt.
Example Output: D

Example Input: [header] How to kill weeds with vinegar [title] Buy white vinegar. [step] Go to your local grocery store and buy a bottle of basic vinegar, typically a 5% concentration of acetic acid. The best bargain is probably to buy a one gallon jug unless you only have a few weeds. <sep> (A) It doesn't have to taste good-just a few drops of the solution can kill any weeds that find their way into your garden. [substeps] The vinegar and pepper helps destroy the remainder of the bermuda grass and virus doing their landscaping. (B) [substeps] Vinegar is one of the best non-identifiable chemicals you can use in your garden as a seed starter. Pop up a bag of pop up soda in a standard metal can and carefully add in 1/2 cup (120 ml) of distilled white vinegar. (C) Add a drop of white vinegar into the bottle and have a close inspection. If you see any areas with a lack of weeds, then vinegar is probably best for killing them. (D) If you are killing a lot of weeds, you may need to buy more than one gallon, but one gallon will cover a large area. [substeps] The acid in vinegar is what kills the weeds.
Example Output:
D