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 improve mental math skills [title] Visualize the equation in your head. [step] The first step in solving a math problem in your head is to visualize the problem mentally. Imagine the numbers and the equation in your head. <sep> (A) As you solve portions of the problem, visualize the new numbers that you're working with. Repeating numbers mentally or verbally, in a whisper, will also help you to remember more significant numbers in the equation. (B) This way, you'll feel this new image when you see your math papers later in the day. [substeps] You may be more aware of your words and body language when you're visualizing the equation. (C) When you picture the equation, you then have a much better time because you are thinking of the process in your head, rather than the equations. [substeps] For example, imagine that math can be only done in a particular time period. (D) When you think about each answer (number, or word) create a picture about what could happen, and then try to make it into a happy picture. Once you have a picture of each answer in your head, work on how to make it into a happy picture of each part of your brain.
Output:
A