You revise a paper after you've written a first draft.
Based on the information provided, the activity of choosing a pattern of organization before beginning a letter represents the planning phase of the writing process. During the planning phase, writers typically consider the overall structure, organization, and content they want to include in their writing. This includes deciding on a pattern of organization, such as chronological order, cause and effect, problem-solution, etc., to guide the flow and structure of their letter. Therefore, the correct answer is option A - Planning.
