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 shampoo hair naturally [title] Combine all of the ingredients. [step] This basic oil and castile soap shampoo formula can help keep your hair glossy and moisturized. Add cup (59 ml) of water, cup (59 ml) of liquid castile soap, and teaspoon (2.5 ml) of light vegetable oil to a bowl. <sep> (A) [title] Place the paste in the proper location for your hair type. [step] If you have curly or wavy hair, your head will need to be covered. (B) [substeps] Massage the mixture into your hair thoroughly to see if it's going to stick. If you've chosen the right shampoo, you should see good results in a week or two. (C) Use a spoon to stir the mixture together until it's fully blended. [substeps] For the best results, use filtered or distilled water. (D) Add warm water to the bowl and stir it with your whisk to disperse the mixture. [substeps] This moisturizing-oil-infused shampoo can help your hair shine.
C