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 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: A man wearing grey shorts kneels down on a carpeted floor and begins stretching. The man moves his right leg under his hip and in front of his left knee. the man <sep> (A) continues exercising his left leg. (B) is then sitting while he's exercising and putting a harness. (C) then begins looking comfortable about doing this and stretches. (D) begins to rock back and forth in a slow movement as he stretches.
Example Output: D

Example Input: [header] How to use superfood powders [title] Choose a single ingredient or multi-ingredient powder. [step] There are two choices when deciding on a superfood powder. You can take a single ingredient powder, like maca, spirulina, or flax seed powder. <sep> (A) Or you can use a multiple ingredient powder, like a synthetically-produced extract, such as grape seed, juniper seed, or shreplywheat. Being able to adjust recipes to any flavor will give you a better chance of success in producing superfood powders. (B) Do some research and see what the colors are like for each ingredient. [substeps] Think about why you want to store a powder in your pantry. (C) You may also choose a powder that combines multiple vitamins, minerals, and superfoods together into one powder. [substeps] Multi-ingredient powders often contain vegetables, like spinach, broccoli, and wheatgrass. (D) You should also choose a single ingredient powder, like cornflour. [substeps] One option is to find one ingredient that is organic or does not contain harmful chemicals like arsenic.
Example Output:
C