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 Q]: [header] How to perform hip flexor stretches [title] Do a yoga camel pose. [step] In addition to stretching the hip flexors, the camel pose will open up the chest and increase the flexibility of the spine. The exercise tightens the waist and strengthens the arms and shoulders as well. <sep> (A) Yogis believe that this posture opens up your respiratory system so that you can take in more oxygen with each breath. They also believe that the exercise helps to open the heart chakra to allow you to feel more connected to the world and to bestow forgiveness where needed in your life. (B) Give yourself a break from the chair and let your head and neck rest against the top of your bar. [substeps] If you're feeling a little fatigued or fatigued, wait a few minutes to give your body time to rest. (C) To do a camel pose, lie down on the floor with your back straight and your feet placed on a park bench. Grip the bars with the weights in your hands. (D) Before attempting these poses, they should be done at home : [substeps] Kneel with your knees bent at a 90 degree angle. Put both of your feet together with your toes pointed in towards each other.
[EX A]: A

[EX Q]: [header] How to introduce a pleco to a goldfish tank [title] Ask how large the pleco will grow to be. [step] Although most pet stores will sell plecos that are only a few inches in length, you should know that they can grow quite large. Fully grown plecos can reach up to two feet in length. <sep> (A) [title] Check your tank's surface before you place the pleco into the tank. [step] Make sure that your aquarium is opaque or has a drop-down tray so that your pleco is not exposed to water. (B) This can have a negative impact on their lifespan. [title] Choose a tank with large walls and no air holes. (C) [title] Make sure you cover more than twice the tank. [step] If you find that your pleco grows too much, cover the entire tank with a blanket. (D) The exact size of the pleco will vary depending on the species. Ask someone at the pet store how large the pleco will get before making a purchase.
[EX A]: D

[EX Q]: [header] How to make a hamster playground [title] Get medium or large cardboard boxes. [step] Use either two large cardboard boxes or four medium sized boxes. Go to a nearby store, or ask your parents to take you. <sep> (A) A larger box should take up less room than a smaller one. If you don't mind going a bit longer, then use a larger box. (B) Try to find boxes that are as clean as possible. [substeps] If you want a pen with higher sides, go with four medium boxes. (C) [title] Cut the pieces of cardboard to size. [step] Then use glue to attach to the sides, and the flaps to the bottom so that the hamster springs out of those boxes once it gets to the outside. (D) [title] Keep the box low to the ground to let it touch the ground. [step] Rock it when it is full with soil, and water it when it is full of loose soil.
[EX A]:
B