Detailed Instructions: 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 get a proper tan [title] Increase your sun exposure gradually. [step] First and foremost, when you begin laying out in the sun, only get 1-2 hours of exposure at a time. Skip a day or two before laying out again. <sep> (A) Melanin, the pigment in your body that colors your skin, is activated when uva and uvb rays from the sun hit your skin. When this happens, more melanin is produced as a form of sun block, or protection from sun damage. (B) [title] Make sure your workspace is in good condition. [step] It is not good for you to be in a tanning bed with no air conditioning, and even worse, in a tanning pool filled with fake-tan chairs made out of commercial materials. (C) Once you're ready, you can begin it all! [substeps] Apply a sunscreen when you're sunbathing. Do not apply sunscreen to your face at night or in the shower. (D) Keep your eyes on your sunscreen as you leave to reapply it. While natural sunscreens may turn out great and fashionable at the same time, they also reduce the amount of melanin in your body, making you less likely to get sunburned.
A:
A