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 relieve constipation after surgery [title] Use a stool softener. [step] One of the first medications to try if you're feeling constipated is a stool softener. These are easy to find over-the-counter and can help get you back on track. <sep> (A) [substeps] The way that stool softeners work is that they draw water into your stool from your intestines. This makes your stool softer and easier to pass. (B) [title] Take 600ml of stool softener before a meal. [step] Most stool softeners kill the production of prostaglandins. (C) [substeps] One good option for relieving constipation at the time of surgery is a stool softener. While stool softeners do provide temporary relief from constipation, they are expensive and will often disappoint you. (D) These medications are named for their antioxidant properties, which help reduce diarrhea and keep your stools from becoming irritated. [substeps] Remember that: the next time you're using an over the counter stool softener treatment, be sure to follow the dosing instructions.
Example Output: A

Example Input: [header] How to survive flight attendant training [title] Pack enough of all the essentials you will need to make it through an extended trip while maintaining a professional appearance. [substeps] Unless otherwise specified in your correspondence from the airline, bring business attire for classroom and training sessions. Bring business-casual attire for down time. <sep> (A) This includes a sweater, gloves, sensible footwear for long car rides, and a carry-on book for your reading habits. First, bring jackets, pants and boots. (B) Some airlines may provide you with a uniform during training, so you won't need to pack as many of your own clothes. Bring anything that will help you have more comfortable and restful sleep, like an eye mask, your own pillow and calming music. (C) Even a range of items such as a fishing belt and sneakers are most effective during this time period. If you know your plane has a get-together with close friends and family, bring along some casual clothes to dress up for your flight. (D) Don't pack clothes that are too formal, too casual, too old-school. The point of switching schools is to have a better idea of what you need to wear.
Example Output: B

Example Input: A group is playing volleyball on a beach. The men volley ball back and forth over the net. one of the players <sep> (A) falls off his board after a serve. (B) falls on the sand. (C) makes it into the net. (D) crashes as he falls onto the ground.
Example Output:
B