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: An athlete practices tossing a javelin in a track a field course. The athlete starts with two or three side steps and then proceeds to toss the javelin. the athlete <sep> (A) then increases his speed and steps. (B) runs parallel to the chalk and throws four instructions that lead into a discus throw, where he throws the javelin as far as he can into the distance. (C) then does a backswing outside of the track. (D) throws the javelin to the other side and then back to the field.
Example Output: A

Example Input: [header] How to stay up late without electronics [title] Drink caffeine. [step] Caffeine blocks neurotransmitters in your brain that make you sleepy. When you start to feel drowsy, reach for a cup of coffee or a soda. <sep> (A) Remember that caffeine loses its effectiveness with overuse. Try to save it for when you really need it. (B) Your body will start shutting down caffeine when you're outside and keep you awake by doing what it is meant to do. It can help you stay awake long enough to go to bed. (C) Though caffeine will not give you energy right before sleep, it will trigger the natural sleep signal that draws us into the world right before it hits. An caffeine-rich beverage will wake you up more, making your sleep better. (D) Coffee is the source of human sleepiness so drinking coffee or another caffeinated beverage before bedtime is important. Even an extra pill is a key lubricant.
Example Output: A

Example Input: [header] How to buy a blackhead remover [title] Learn your options. [step] You should not squeeze or pick at blackhead, as this can lead to infection or scarring. However, you can remove pesky or unsightly blackheads with several different types of products that may not necessarily irritate your skin or require treating it with chemicals. <sep> (A) Learning your different options can help you identify the best product for your specific blackhead removal needs. Products that can remove blackheads include : [substeps] Extractor tools pore strips clay masks topical creams [title] Identify the best remover for your skin type. (B) For example, cleansing a burnt face can peel pores, like blackheads, and subtly remove blackheads. Deep pore pimples, which are a common factor for blackheads, are not tended to dry out. (C) [substeps] Avocado, keratin, and brewer's yeast all work well in reducing the inflammation and scarring of blackheads. [title] Pick a chemical neutralizer for stubborn blackheads. (D) Some of the well known brands that are known for their blackheads include tootane, steam, huawba, and celandine. As noted above, these products are more environmentally friendly than other skincare products, especially for those kids.
Example Output:
A