What qualitative method can indicate adequate airflow at a vent exit?

What qualitative method can indicate adequate airflow at a vent exit?

• A. Use a digital manometer to measure static pressure at the vent.
• B. Observe airflow visually or with a smoke pencil or tissue to confirm movement.
• C. Install a hygrometer to measure humidity at the vent exit.
• D. Use a flux meter to determine airflow.

Answer: (B)