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 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.

Ex Output:
A

Ex Input:
A small group of children are seen standing before a mat with an instructor helping. the girls <sep> (A) then begin throwing a rope to the back and covering the boys head with the rope. (B) then pole vault on the mat and swing during a routine. (C) do various gymnastics moves across the mats while an instructor assist them and another points to the side. (D) take turns running to the mat and pushing it down.

Ex Output:
C

Ex Input:
[header] How to de poof hair [title] Avoid washing your hair every day. [step] Hair gets poofy and frizzy when it's dry. While washing your hair cleans it, it also strips your locks of the natural oils that keep it moisturized and more manageable. <sep> (A) What will help dry out your hair most is the natural oils. [substeps] Try to shampoo or condition your hair every day. (B) This is especially important when you shower, or when you're sweating. Avoid washing your hair with your showers, as this can cause or even split your hair pieces. (C) If your hair is particularly oily, never wash it more than once a day. [substeps] If you normally wash your hair a lot, try making a point of making this a habit. (D) To keep your hair from getting poofy, wash it every other day at most. [substeps] If you already wash your hair every other day and it's still poofy, try two days between washes.

Ex Output:
D