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".

Example 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.
Example Output: C

Example Input: [header] How to visit the top 10 tourist destinations in london [title] If you are planning to visit london why not try visiting the following must-see places? [title] Visit the british museum at great russell street. The british museum's art collection includes artworks from all over the world. [step] The british museum houses the rosetta stone, sculptures from parthenon, and the portland vase. <sep> (A) Visit art galleries, amazing places, and places which you have never been. [substeps] Do not forget to ask for drivers from the london lights station, trinity quarter , 121 lights avenue-this is the only modern route to london. (B) The british museum is considered as one of the best in the world and it was established in 1753 via the act of parliament. The first collections were from sir hans sloane. (C) They are also accessible by either gps or facebook. [substeps] If you are going to the london museum, press the' get started' button. (D) Occasionally you may see art museums in london that serve as places to observe british history-like the australian museum. [title] Then take the ferry from oxford to mcdonald's, the capital city of london.
Example Output: B

Example Input: [header] How to make converted rice [title] Using a formula of 1 part converted rice to 3 parts water, mix together the water and rice in a large pot with a lid. [step] For 2 servings, that would be a 1/2 cup rice and 1 1/2 cups water. [title] Add some fat. <sep> (A) [step] Put some fat into the water mixture to make the water boil. [title] Boiling the water helps the oil to release and will loosen the starchy cells. (B) [step] Use 3% fat found in fish foods (fish oil is relatively safe) and you should probably use tofu. A thick amount is a good amount but you can technically do more or less. (C) [step] Drizzle some fat over all of the rice. Be sure to choose peanut fat, however be careful not to over saturate the rice. (D) [step] Add 1 tablespoon of oil, margarine or butter to every 1/2 cup of rice in the pot. [title] Cover the pot and bring the water to a boil.
Example Output:
D