Ans. c is correct because ventilation process is happen due to the process of convection. e.g.sea breeze and land breeze.

**Ventilation in the room is due to convection.**

**Explanation:**

Ventilation refers to the process of bringing fresh air into a room or space and removing stale air. It helps to maintain a comfortable and healthy indoor environment by regulating temperature, humidity, and air quality. Convection is the main mechanism behind ventilation in a room.

**Convection:**
Convection is the transfer of heat through the movement of fluids, such as air or water. In the context of ventilation, convection occurs when warm air rises and is replaced by cooler air. This creates a natural airflow within the room, allowing fresh air to enter and stale air to exit.

**How convection works in room ventilation:**
1. Warm air rises: When air inside a room is heated, it becomes less dense and rises towards the ceiling. This warm air carries moisture and pollutants with it.
2. Cooler air replaces warm air: As the warm air rises, cooler air from outside or other areas of the room flows in to replace it. This creates a continuous cycle of air movement.
3. Fresh air enters while stale air exits: The influx of cooler air brings fresh oxygen into the room, while the warm air carrying moisture and pollutants is pushed out through openings such as windows, doors, or ventilation systems.
4. Natural air circulation: The movement of air due to convection creates a natural air circulation pattern within the room, ensuring a constant supply of fresh air and maintaining a comfortable environment.

**Other mechanisms not responsible for room ventilation:**

- Conduction: Conduction is the transfer of heat through direct contact between objects or materials. While conduction can contribute to the transfer of heat within a room, it is not the primary mechanism responsible for ventilation.

- Radiation: Radiation is the transfer of heat through electromagnetic waves. While radiation can influence the overall temperature of a room, it does not actively contribute to the movement of air or ventilation.

**Conclusion:**
Ventilation in a room is primarily due to convection, which involves the natural movement of air caused by the rise of warm air and the influx of cooler air. This convection process ensures a continuous supply of fresh air and removes stale air, contributing to a comfortable and healthy indoor environment.