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 Input:
[header] How to choose a protein supplement [title] Choose whey protein to build muscle. [step] If you're looking for muscle-building protein, whey protein is generally your best option. Whey protein can come in the form of powder or pills and is commonly used when people are trying to build muscle via things like weight training programs. <sep> (A) By doing this, you're gaining more body fat and growing more muscle at the same time. [substeps] Whey protein can be found in half of the packaged foods. (B) Whey protein is also a low-fat protein, rich in red blood cells from bacteria. Although whey protein does not impart healthy fats to the body, whey protein helps build muscle, which you can grow and burn through exercise. (C) [substeps] Look for a whey protein powder or supplement with a high biological value. This measures how well your body can absorb the protein. (D) Whey protein occurs as a food chain, hence the slogan, " protein is fat free ". [substeps] Whey protein is complex and varies from patient to patient.

Ex Output:
C

Ex Input:
[header] How to be a cute girl in middle school [title] Maintain good personal hygiene. [step] To look fresh and clean, make sure you shower and wash your hair regularly. Brush your teeth before school each morning, and wash your face with a facial soap of your choice. <sep> (A) Brush and floss twice a day to get rid of dead skin. Be sure to use a good shampoo on your hair. (B) [substeps] Wear deodorant to keep you smelling fresh, especially if you'll be participating in gym class or an after-school sport. Aiming to wash your hair every other day is a good way to keep your hair clean and healthy. (C) Make sure your clothes are clean and free of dirtiness. Don't wear baggy or silly clothes, as you don't want to show off your physical body. (D) Then for the day, put on clean, feminine clothes, which in this case will be sweatpants, ballet flats, a clean shirt, and a cute pair of fluffy sneakers. Apply body conditioner to your hair daily to hold it in place until you get out of class.

Ex Output:
B

Ex Input:
[header] How to collect cards at your wedding [title] Use a secure card box. [step] If you choose to collect cards using a card box, make sure it is secure. Choose a card box that has a lock. <sep> (A) Then, use your card box's key combination to secure it. Put the key combination in the " + " on your card box or off to the side. (B) The card box should have a single slit in the top. It should remain locked throughout your wedding festivities. (C) This will make it easier to access your cards at the wedding. [substeps] There are a number of card boxes that you can purchase at your wedding shop, but any one that you choose needs to be secure. (D) This provides security for your guests who want to know the card contains secrets. [substeps] If you add valuables into a box, make sure there are locks at the bottom of it.

Ex Output:
B