单项选择题

A.左上角为原点(0,0),右下角为(Screen.Width,Screen.Height)
B.左下角为原点(0,0),右上角为(Screen.Height,Screen.Width)
C.左下角为原点(0,0),右上角为(Screen.Width,Screen.Height)
D.左上角为原点(0,0),右下角为(Screen.Height,Screen.Height)