下列JApplet实现了一个多行文本输入区和一个按钮，单击按钮则清空文本区内容，文本区使用带标题的

边框。选择正确的语句填入横线处。 import javax,Swing.*; import java.awt.event.*; import java,awt.*; public class ex26 extends Japplet { public void init() { Container cp = getContentPane(); Jbutton jb = new Jbutton("清空"); final JTextArea jta = new JTextArea(); jb.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent ae) { jta. setText (""); } }); cp.add("South", jb); cp.add("Center", jta); } } { jt

A．setBorder(BorderFactory, createTitledBorder("文本区"));

B．cp.setBorder(BorderFactory, createTitledBorder("文本区"));

C．jta.setBorder(BorderFactory, createTitledBorder("文本区"));

D．jta.setBorder(Border, createTitledBorder("文本区"));