When should cargo be inspected during a trip?

Answer: D — Every three hours or 150 miles after every break

During a trip, cargo should be inspected every three hours or every 150 miles after every break. This is because cargo may shift during transportation and it is important to check for any damage or shifting that may have occurred during the trip. Inspecting every hour (option A) may be too frequent and not necessary, while inspecting every two hours (option B) may not allow enough time for any significant changes to occur. Inspecting every five hours (option C) also may not be frequent enough to catch any potential issues. Therefore, option D offers the best balance between frequency and distance covered.