Definition: 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". 
Input: [header] How to make colored ice [title] Get out your ice cube tray and pour water into it. [step] Make sure you don't put too much water in, or else it will overflow and it will not work. [title] Add in the food coloring. <sep> (A) [step] Add 2 to 4 drops of food coloring into the water or you are done. The more colors you use, the faster you will get a color for your ice cube tray. (B) [step] Some people prefer to use color as the ice tonic. This way, you can achieve different colors! [substeps] For example, if you want to make apple ice, use gel food coloring. (C) [step] ( the food coloring should be even, but it should look an a + + ) [title] Add the ice cream. [step] Stir continuously and keep switching at least every 5 minutes so it stays thick. (D) [step] The food coloring can be any color you want. The more drops you put in the darker it will be.
Output:
D