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 stretch to improve your flexibility [title] Warm up your muscles. [step] Perform 40 jumping jacks , 25 squats, run on the spot for 5 minutes, and ten press-ups or ten girl press-ups if you are not strong enough. [title] Start with simple stretches to get used to the concept and feeling of stretching. <sep> (A) [step] You can stretch on a ball or in the sky. Avoid attempting to do anything difficult or hard and figure out what you're doing properly. (B) [step] Does it feel to stretch? That is great. Start slow and do thirty chest presses before you reach bench pressing. (C) [step] Stretching is the single best way to exercise comfortably and to elevate your blood circulation. [title] Work your muscles with the backbend workouts. (D) [step] Stand up and stretch your legs into a wide straddle. Reach down until your palms rest on the ground, keeping your legs straight.

Ex Output:
D

Ex Input:
[header] How to measure clothing for your cat [title] Measure a calm cat. [step] Catch your cat in a good mood, or a sleepy mood. Wait until your cat is holding still, and take his or her measurements. <sep> (A) Remember to ask beforehand if the cat's body language indicates a calm individual. [substeps] If your cat is growling, meowing, or hissing, this indicates a calm individual. (B) Your cat may jump up to grab the measuring tape or unlike with its usual behaviour. Make sure your cat stays still and seem both calm and alert. (C) If your cat is hyper, play with him for a while and gradually calm him down. For example, let your cat chase a toy for a while, then let him catch the toy. (D) Cat fur is a delicate fabric, and your cat will be easily scratched if you mess up the measurements. [title] Put your cat in a comfortable place.

Ex Output:
C

Ex Input:
[header] How to fit a mortice deadlock [title] Measure where the lock will fit on the door. [step] As a guide, the height of your lock should be about 1 metre high. [title] Using your measurement, mark out both the top and bottom of the latch. <sep> (A) [step] To determine the height, measure out 1 metre high. It's easier to fit a mortice lock and reverse the measurement before final locking. (B) [step] That is, hold them straight with your fingers pointing outwards, while you measure them out on the outside. And that means the edges of the lock should match the lines on each side. (C) [title] Weigh the weight of the mortice (or combination lock) against the weight of the lock. [title] Have them fit together by applying two coats of interior caulk to their sides. (D) [title] Measure and mark out a vertical central line. [step] This will be your guide when drilling.

Ex Output:
D