单项选择题
When you open a file or run a program in a computer, a window appears on the desktop of your computer. The () of the window indicates which program you are currently working in arid its color will become blue if a window is active. When you click on The () , the window disappears and appears as a button on the taskbar. Clicking on a button in () will invoke a specific command.
When you click on The () , the window disappears and appears as a button on the taskbar.
A.maximize button
B.restore button
C.close button
D.minimize button