Which statement about respiratory droplets is true?

• A. They do not stay in the air as long.
• B. They stay in the air longer than airborne particles.
• C. They are larger and fall out of the air quickly.
• D. They have no role in disease transmission.

Answer: (A)

Respiratory droplets are relatively large particles expelled when a person talks, coughs, or sneezes. Because they’re heavy, gravity pulls them down quickly, so they don’t linger in the air for long and usually travel only short distances before settling onto surfaces or a person nearby. That makes the statement about not staying in the air as long true, since droplets don’t stay suspended the way smaller airborne particles do. The other options misstate the nature of droplets: aerosols (not droplets) stay in the air longer, droplets can still transmit disease when they land on mucous membranes or surfaces, and saying they have no role in transmission isn’t accurate.