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 install custom firmware [title] Record the router's model and version number. [step] These numbers are usually located near the manufacturer's logo, underneath or in back of the router. Write down the model and version information for future use. <sep> (A) [substeps] If you are using windows xp (default operating system), the model number can be found in the start menu under " system settings. " skip all the discussion menus, and then go to system preferences. (B) [title] Obtain the router's ip address and default gateway for your computer system. [substeps] Determine the ip address and default gateway for a pc. (C) [substeps] " w " with the green background is the serial number for the model. " p " with the red background means " unhappy operating system. (D) [substeps] It is easy to determine what operating system is running on your router if you don't know the model. Copy the model from the registry to convert it to your operating system.

Output: B


Input: Consider Input: [header] How to avoid water retention [title] Have a healthy diet. [step] Ensuring you have a healthy, balanced diet is a good first step to avoid water retention. Water retention can occur due to imbalances in your diet, deficiencies of some vitamins and minerals, and having too much salt. <sep> (A) One study found that people with excess salt = no water retention. " imbalance " can add up as a reason for water retention and include making it much more difficult to stay hydrated. (B) Excess salt raises your blood pressure, resulting in inaccurate results. Look for foods that are low in salt and low in water. (C) Eating a balanced diet will help to reduce the chances of water retention occurring due to these issues. [title] Eat food that is rich in potassium. (D) [substeps] If you have recently cooked or baked a meal, make an effort to change your recipe one day. This can help your body prevent the retention.

Output: C


Input: Consider Input: [header] How to prepare bok choy [title] Buy bright, firm bok choy for eating raw. [step] Bok choy is perfectly fine and tender for eating raw, especially with the right pairings in a salad. If you're going to eat raw bok choy, buy them small and brightly colored. <sep> (A) Bite into the flesh to get its sweetness and firmness. [substeps] Bok choy can be raw, fresh, or diced. (B) [substeps] Leftover bok choy should only be eaten plain or fresh. [title] Store bok choy for following foods. (C) You'll also be breathing in the fumes of this meat so be sure to leave room for fresh or tender bok choy. [title] Find fresh and unbruised bok choy slices for topping. (D) Young bok choy is tender and delicious. [substeps] Most bok choy is fairly limp, compared to heftier lettuces and other greens, so that's not necessarily a sign of quality.


Output: D