The correct option is C Cold air flows from sea to land during the day.
Sea breeze is a convection phenomenon that happens due to uneven heating of the air above the sea and the land, by the sunlight. During the day, the air over the land is heated quicker than that over the sea. Due to this, cold air starts to flow from over the sea toward the land. This results in a cool breeze from the sea, when we go to a beach during the day.