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 sell dvds on amazon [title] Register for an amazon seller account. [step] Go to amazon's seller central site to sign up for a third party seller account. Fill out the registration form with your name, email address, and unique login password. <sep> (A) Once your account has been activated, you'll be able to sell your used items on amazon. [substeps] You may also be asked to provide some basic financial information, such as your debit card or bank account number. (B) Agree to the terms and conditions of the seller account and click on " register " at the bottom right of the page. You will receive your cd rental rights next to your name. (C) [title] Copy your dvd, videos, or files onto your home screen using the same link on the seller main page. [step] Make sure this link is easy to write and that your dvd is in a separate folder for storage purposes. (D) Most sellers will require you to provide a proof of registration and identification number before you can register. [substeps] If you don't yet have an amazon account, you can register this online or in person.
[EX A]: A

[EX Q]: [header] How to study the phenomenon of light as a nonequilbirum state of matter [title] Understand how thermodynamic systems are categorized. [step] Thermodynamic systems in nature are divided into two types. One is systems that are at equilibrium state with the environment and the other is systems that are in a state of nonequilibrium with the surroundings. <sep> (A) On earth, nature has a preference for systems that are at an equilibrium state with the surrounding. This is so due to the principle of minimum energy that every object in the universe aspires to have. (B) For example, gas rising in temperature throughout the day can be divided into microorganisms in the environment. [substeps] For example, gas rising in temperature in the atmosphere can be divided into molecules in the environment. (C) [substeps] Equilibrium is fundamental in thermodynamics. Other systems include stars, planets, and oceans. (D) [title] Learn about the term " rock hydrodynamics ". [step] Rock hydrodynamics refers to the transfer of water to the earth's surface.
[EX A]: A

[EX Q]: [header] How to finish maple [title] Sand the project you have made from maple wood using progressively fine sandpaper of 120 to 320 grit. [step] Finishing this tight will help close up the pores of the wood in preparation for staining. [substeps] When sanding is complete, wipe down the entire maple project with a lint-free cloth. <sep> (A) Rag off any excess dust as you go along. You don't want to smudge or drip the wood while sanding. (B) This removes dust that was left over from the sanding. [title] Choose a type of stain within your skill set as it can be a challenge for the beginner. (C) [title] Decide which side of the maple will be the body. [step] Every method is different, so have someone start working from the back side and you go. (D) [title] Sand the pressboard windows with 120-grit sandpaper applied to top of window. [title] Wipe down the sunglass windows with 150 to 150-grit sandpaper applied to top of panel.
[EX A]:
B