Case Description: A historian compared an early city census with tax rolls compiled the same year. The tax rolls list many household heads absent from the census, especially tenants in crowded waterfront buildings. Yet the rolls omit most dependents and some residents exempt from taxation. The comparison strongly suggests that the census undercounted households in particular districts, but it cannot yield an exact population correction simply by adding every tax-roll name. Propositions: A1. Some household heads appear in the tax rolls but not in the census. A2. The tax rolls provide a complete list of every resident, including dependents. A3. The evidence points to especially serious census omissions in crowded waterfront areas. A4. Adding all tax-roll names to the census would necessarily produce an exact corrected population total. Which choice matches the full set of statements for which the passage supplies adequate support? Evaluate each claim separately before comparing the sets.