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".

[Q]: [header] How to use psychology to close more sales [title] Give something for free. [step] The principle of reciprocation is a psychological phenomenon described by dr. robert cialdini, an expert in persuasion. According to this theory, it is part of human nature to feel obligated to repay debts of all kinds, big and small. <sep> (A) To begin this process, ask yourself if you really are willing to sell something for free. If you are willing to throw in the money, then you are probably willing to take credit. (B) You can't force anything on someone else. [substeps] If you " feel " obligation to a friend or loved one, give them something to ask you " if i use this method, what will happen? " [title] Assemble your argument. (C) If someone receives something free, they will feel a psychological urge to purchase a product to pay you back for your kindness. [substeps] Offer a free trial period, a sample, or even a pleasant experience. (D) To do this you must pay for or at least accept the full offer. After that you must devise a plan of compensation.
[A]: C

[Q]: [header] How to treat cold sores in your nose [title] Figure out if you have cold sores in your nose. [step] Because it is difficult to see inside of your nose, you may need to figure out if you have cold sore instead of another condition such as an ingrown hair or pimple. Checking the areas in and around your nose can help you figure out if you have cold sores in your nose. <sep> (A) [substeps] Check your nose from the bottom of your nose, just in front of your cheekbone, towards your chin. If it feels numb, there is probably something there. (B) [title] Determine if you have a stuffy nose. [step] In your nose, you may need to take some pressure off of the bridge of your nose and see if that pressure is gone or causes the discomfort. (C) [substeps] Use a mirror to check the visible surfaces of your nasal cavity. You may not be able to see much, but even detecting a cold sore can help. (D) [substeps] To figure out if you have cold sores, you may be looking in your nose. Either look back at the corner of your nose, or look to the floor.
[A]: C

[Q]: [header] How to sign a credit card [title] Find the signature bar. [step] This will be located on the back of the card. Flip the credit card over so you're looking at the reverse side, and look for the light gray or white bar. <sep> (A) If the credit card is issued from a different country, the background of the signature bar will consist of a variety of dials with different cents written inside. Usually newer cards will say " quarters/miles/miles. (B) [title] Write on the reverse side of the card. [step] There will be four small characters on it in white lettering. (C) [substeps] You'll see that the phrase " signed in " will appear in the upper right corner of the card. [title] Put your current id information into the card. (D) [substeps] Some cards may have an adhesive sticker over the signature bar. If yours does, remove the sticker before signing.
[A]:
D