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". 

[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.
C

[header] How to determine who has right of way [title] Come to a complete halt at a stop sign or red light. [step] At a stop sign, come to complete halt for about 2 seconds or until vehicles that arrived before you clear the intersection. If you're stopped at a red light, proceed when the light has turned green. <sep> (A) This will give you enough time to catch the light and clear the intersection. [substeps] Vehicles behind or behind you may not brake. (B) This blocks oncoming cars from passing you. [substeps] If in doubt, you can also tell if you're going too fast by looking ahead at the tires of that car. (C) If you are stopped before a red light signals for another vehicle, you're on your own. [substeps] This means every car crossed before you has passed, and every vehicle in the intersection has stopped before you. (D) If the intersection has a white stripe in your lane, stop before this line. [substeps] If you have a stop sign, but the street you're crossing does not have a stop sign, wait until all traffic has cleared before crossing the intersection.
D

[header] How to maintain clear skin [title] Wash your face every morning and night. [step] This helps get rid of germs and bacteria along with other debris that can clog your pores and cause blackheads and acne. [substeps] Wet your face with cool water. <sep> (A) Then using your fingertips massage your skin on both sides of your face. Lightly rub your facial skin to remove all of the dirt and debris from your face. (B) Hot water is harsh on skin and will strip your skin of its protective oils. Cool water, on the other hand, can help prevent your face from overproducing oil. (C) Then place your face over your mixing bowl or plate. Place your face over your mixing bowl with your dominant hand (hand free if possible) and your other hand (hand free if you have your hand free. (D) Use two fingers to gently swab your skin in circular motions. Gently sponge your face with your fingertips to help remove all impurities.

B