You will be given a definition of a task first, then some input of the task.
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 get grey blue hair [title] Evaluate your current shade. [step] If your hair is medium brown or darker, this look can be difficult to achieve. You'll have to bleach your hair two or three times to get it light enough to apply the grey-blue tones. <sep> (A) However, you can still achieve grey hair by changing your color or by mixing your hair dye with a developer. Try to match the hue of your hair to your current shade. (B) And since you'll only be dying this dye for three or four years, rinse it out and select a shade that's right for you. [substeps] Grey hair can come in many different shades, from platinum blonde to gray. (C) If your hair is very light brown or darker, the grey-blue colors and the blue mix well. If you can achieve this look, say you want your hair to look like grey. (D) Bleach is very damaging to the hair, so waiting 3 to 6 weeks between bleaching sessions is recommended. If you still want to go for it, just know that you'll have to invest quite a bit of time and energy into getting there, and you may significantly damage your hair in the process.
Output:
D