Concept:Process writing is called a bottom-up approach because it builds a piece of writing step by step from small components to the final text.Explanation:In process writing, students start by generating ideas. Then they organize these ideas, considering purpose and audience. Next, they choose words, review grammar and logic, verify information, and finally share with a real audience. This progression from basic elements to a complete draft is a bottom-up method. It emphasizes continuous revision and refinement over several sessions.Answer:Bottom-up approach (Option C).