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 befriend dogs [title] Make sure the dog is friendly. [step] When approaching a strange dog, be particularly aware of its body language. If an owner is present, ask the owner if the dog is friendly. <sep> (A) Make sure the dog wants to be petted. You can easily alienate a dog by approaching one that is nervous or agitated. (B) If a dog seems hesitant to meet you or extends its hand to you, it's the opposite of friendly. [substeps] Avoid approaching a dog by walking near it and stopping so that the dog can see you. (C) Usually, a dog looks friendly when greeting a stranger but when the dog is not, try something more benign. [substeps] Some common signs of friendliness on dogs are legs waving, laughing, and shoulder-shaking. (D) Common signs of friendly behavior are not always direct stares. If a stranger approaches the dog, its body language may indicate a definite dislike.
[EX A]: A

[EX Q]: [header] How to polish rocks [title] Choose the right rock. [step] You can polish any stone you wish, but there are certain characteristics of a stone that will make it easier to polish. If you want an easy stone to polish, pick a somewhat softer stone like onyx, limestone or calcite. <sep> (A) [substeps] You can polish diamond, granite or ceramic stones by cutting thin pipe holes or inserting dry mortar into one side of each hole. Look for a stone that resembles a diamond, but not necessarily a diamond. (B) Otherwise, a smoother, more pumice-like stone will be more difficult to polish. [substeps] Emeralds and equilateral manganese are both excellent mineral polishes. (C) Stones that are very hard will take a much longer time to polish. However, though hard rocks take a long time to sand, they yield more shine than softer rocks. (D) Softer rocks will actually work more well, and might look better to polish very old stones, but brighter stones tend to chip quicker. [substeps] Rubies, sapphires, and emerald are good options.
[EX A]: C

[EX Q]: A man wearing scuba gear walks along the edge of a swimming pool. The man starts talking to the camera and shows the camera various items. the camera <sep> (A) captures his underwater view while he talks. (B) shows the swimming pool. (C) zooms in for a closer look of the man swimming under the pool. (D) pans left and fishes for the fish that are swimming under the water.
[EX A]:
B