Assess students' ability to calculate and compare carbon emissions and annual costs for four daily commuting options—car, bus, bicycle, walking—based on a typical high school student's weekly schedule (5 days, round trips). Using provided emission factors (e.g., g CO2 per passenger-mile), fuel and fare prices, bike maintenance estimates, and school-year length, students should compute per-trip, weekly, and annual emissions and costs, perform necessary unit conversions, identify lowest-emission and lowest-cost options, calculate break-even distances or cost thresholds, and justify recommendations with clear assumptions and step-by-step calculations.