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". 

Input: Consider Input: [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.

Output: C


Input: Consider Input: A small group of people are seen lifting a large object into the back of a van and close ups of them and a building. The people are seen riding around a large gymnasium on roller blades performing various flips and tricks. the boys <sep> (A) continue skating around and interacting with one another and performing impressive tricks. (B) continue riding around a sports stadium and performing tricks. (C) play the drums while riding around on bouncy chairs that run in a tight group. (D) ride around again in the end with more people watching on the side.

Output: A


Input: Consider Input: [header] How to treat a sea urchin sting [title] Recognize a sea urchin sting. [step] In order to treat a sea urchin sting, you must be certain you were stung by an urchin and not another marine animal. [substeps] Sea urchins have flat or globe shaped bodies and are covered in spines. <sep> (A) Sometimes they have pinholes on their faces or quills on their red gills. They also have large, round eyes that are reddened from hard sun exposure. (B) But when you see an individual in an animal scene or from behind, you may be able to see their tooth resting on their lips in an attempt to bite the skin. To see if there is another animal in the scene, you will not have to do anything else to confirm your senses. (C) They are found in oceans worldwide, but are more likely to be present in warmer regions. Sea urchins lurk in rocky parts of the water and will sting if threatened. (D) They also carry a large head, which irritates the skin on the face because they pick up a lot of the content and skin lies atop them. Be aware that these may be very expensive when it comes to caring for a sea urchin bite.


Output: C


