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 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.

Ex Output:
A

Ex Input:
[header] How to make fruit crisp [title] Preheat your oven to 350 degrees f (175 degrees c). [title] Coat the bottom of a 9 x 12 baking dish with butter. [substeps] Use a stick of butter from the refrigerator to prevent clumps on the dish. <sep> (A) Fold the top two or three times so the butter is completely mixed in. [title] Place an inch of butter in each of the bottom four corners of the pan. (B) Use a butter knife to remove excess butter. Use a spatula to score small bumps on the surface of the dish by lightly tapping the butter over the area. (C) You will not need to use the entire stick, so only expose 1 end of the butter. [title] Make fruit crisp using a variety of fruits. (D) [title] Wash two large fruit pistachios in warm water. [title] Mash them with a fork or another food processor until they are smooth.

Ex Output:
C

Ex Input:
[header] How to collect email addresses [title] Create a sign-up sheet. [step] If you have an actual storefront, place an e-mail sign-up sheet near the register. Point it out to each customer who makes a purchase. <sep> (A) This will hold the full month's sales price because the business's members will not need to sign-up. Plan to take into account the current set of needs for the business as well as the current challenges it may face financially. (B) Sometimes you may also wish to advertise by adding the name of your company into the business sign-up sheet. [substeps] For example, if your office features a storefront, point your e-mail door in that direction. (C) [title] Copy e-mail addresses from customers instead of typing them in. [step] Print off enough e-mail addresses to collect as many e-mail addresses as you want from everyone but your customer. (D) [substeps] Similarly, you can instruct your cashiers to ask each customer who approaches the register for an e-mail address. Make sure that your cashiers tell your customers that providing an e-mail address is only optional while explaining the benefits of doing so.

Ex Output:
D