单选题：What best describes the appearance of an application with the fo

What best describes the appearance of an application with the following code? @[B](2)
```Java
public class App extends JFrame{
public static void main(String argv[]){
App app=new App();
app.setLayout(new FlowLayout());
app.pack();
app.setVisible(true);
}
App(){
add(new JButton("One"));
add(new JButton("Two"));
add(new JButton("Three"));
add(new JButton("Four"));
}
}
```

A. A frame with buttons marked One to Four placed at each edge
B. A frame with buttons marked One to Four placed one by one
C. A frame with one large button marked Four in the Centre
D. A frame with buttons marked One to Four placed in grids




A.A frame with buttons marked One to Four placed at each edge
B.A frame with buttons marked One to Four placed one by one
C.A frame with one large button marked Four in the Centre
D.A frame with buttons marked One to Four placed in grids


答案：B