1. The problem asks which organizational structure is best for writing instructions to build a birdhouse. 2. Let's understand the options: - Cause and effect explains reasons and results. - Order of importance ranks ideas from most to least important. - Compare and contrast shows similarities and differences. - Chronological order arranges steps in the sequence they occur. 3. Instructions for building something require clear, step-by-step guidance. 4. Therefore, the best structure is chronological order, which presents steps in the order they should be done. 5. This helps the reader follow the process easily and successfully build the birdhouse. Final answer: 4) chronological order