The correct answer is option 'B', which states that sea breeze and land breeze are caused by the currents set up in the air due to convection. Let's understand why this is the correct answer in detail.

Sea breeze and land breeze are two different types of local winds that occur near coastal areas. They are both caused by the uneven heating of land and water, which creates a difference in air pressure and sets up convection currents in the air.

Land and water have different heat capacities, which means they absorb and release heat at different rates. During the day, the land heats up faster than the water because it has a lower heat capacity. As a result, the air above the land becomes warmer and rises, creating a region of low pressure.

**Sea Breeze:**

1. During the day, the land heats up faster than the water, causing the air above the land to become warmer and rise. This creates a region of low pressure over the land.

2. The cooler air from the sea, which has a higher pressure, moves towards the land to fill the vacuum created by the rising warm air. This movement of air from the sea to the land is called a sea breeze.

3. As the sea breeze moves inland, it cools the land and provides relief from the heat. It is often accompanied by a gentle breeze and may bring a slight increase in humidity.

**Land Breeze:**

1. At night, the land cools down faster than the water because it has a lower heat capacity. The air above the land becomes cooler and denser, creating a region of high pressure.

2. The warmer air from the sea, which has a lower pressure, moves towards the land to fill the vacuum created by the cooling air. This movement of air from the land to the sea is called a land breeze.

3. The land breeze is generally weaker than the sea breeze and may bring cooler temperatures and drier conditions.

**Convection and Local Winds:**

Convection is the process of heat transfer through the movement of a fluid (in this case, air). The uneven heating of land and water creates temperature differences, which cause the air to rise or sink, setting up convection currents.

In the case of sea breeze and land breeze, the temperature differences between land and water lead to the formation of convection currents in the air. The warmer air over the land rises, creating a region of low pressure, while the cooler air over the water sinks, creating a region of high pressure. This pressure difference causes the air to move from areas of high pressure (sea) to areas of low pressure (land), resulting in the sea breeze and land breeze.

In conclusion, sea breeze and land breeze are caused by the currents set up in the air due to convection. The uneven heating of land and water creates temperature differences, which lead to the formation of convection currents and the movement of air from the sea to the land (sea breeze) during the day, and from the land to the sea (land breeze) during the night.

Land breeze blows during the night from land to sea and the land becomes cooler faster than sea the air above the sea becomes dense and rises the cooler air from the land moves into take its place sea breeze blows during the night the day and the land heats up faster than sea so correct answer is 'B'