Given the task definition and input, reply with output. 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".

[header] How to prevent kidney stones in dogs [title] Make sure that your dog always has access to fresh, clean water. [step] Water helps to dilute your dog's urine, which keeps the minerals in the urine suspended in fluid. Drinking enough water also makes your dog urinate on a regular schedule, which helps to flush the minerals in the urine from your dog's body. <sep> (A) [title] Make sure that your dog's water bowl is and properly fitted with a water bottle. [step] Check the bottles at your pet store and make sure that your dog's bowl has correctly fitted and is a proper height. (B) [substeps] Change your dog's water every day and clean his bowl a few times a week to minimize bacteria. [title] Give your dog the right amount of water every day. (C) [title] Try to lower your dog's weight. [step] If your dog has kidney stones, it may be hard to keep the weight down. (D) Avoid water with added electrolytes, which can lead to kidney stones. [substeps] Your dog's water bowls are one place that should never be refilled since their surfaces can be contaminated.
B