【单选题】

Children in the US

A、like KDay very much. K is for kites. March the 7th is the day. On that day lots of children go out in the open air. They take their kites with them. Some kites are very big. Others axe small. They are in different colors.Every kite has a long string. To get the kites up, the children begin to run. Now all of the kites are high up in the air. The one like a bird is the highest.
______ a lot of children go out to fly kites.
A、On 7, March
B．On Sunday
C．On Saturday