Definition: 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".
Input: [header] How to help your guinea pig live a long life [title] Buy the right cage. [step] Provide at least 10 square feet of living space for two guinea pigs. This space prevents conflicts between males, fighting between guinea pigs, and reduces the risks of bloat, obesity, and gas build-up by providing adequate room to exercise. <sep> (A) Make sure you adjust the temperature as often as you can, as guinea pigs thrive in a climate that is comfortable for their body. [substeps] Choose a larger cage for a small mouse or little mouse which will be able to move around comfortably. (B) [title] Check for the right size for your guinea pig. [step] The smallest cage will suffice for one guinea pig. (C) Your guinea pig needs at least 12 square feet of floor space to exercise at its maximum level of fitness, and at least 20 square feet of space to eliminate clutter and to maintain healthy litter levels. [substeps] You'll need an overly wide cage large enough for five males. (D) [substeps] Test a few cages and look for one that you can clean easily. Can your hand enter the cage easily? Can you use a brush inside it? Make sure that the cage is light enough to keep your guinea pig happy.
Output:
D