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".
Q: [header] How to bleach dark brown or black hair to platinum blonde or white [title] Check if your hair is healthy enough to withstand bleaching. [step] There is no way to avoid the serious damage to hair that this amount of bleaching incurs. Some stylists won't bleach hair that has already been color-treated or processed. <sep> (A) Ask your stylist if your hair is healthy enough for bleaching. [title] Check when bleaching your hair. (B) However, you can always check to see that your hair is healthy enough for the bleach to penetrate the rest of your hair. [title] Use a 0 to 1 ratio of bleach and mineral and ammonia. (C) Check with your hairdresser in advance to avoid disaster. [title] Set aside an adequate amount of time. (D) The hair that is not being bleached may burn or get discolored from the bleaching process. Your bleach needs to be light blonde.
A:
C