如果需要禁用默认的虚拟主机，并启用blog.mytest.com虚拟主机，应使用下面哪条命令( )

A.sudo a2ensite 000-default &&sudo a2dissite blog.mytest.com

B.sudo a2dissite 000-default &&sudo a2ensite blog.mytest.com

C.sudo a2dissite 000-default &&sudo a2dissite blog.mytest.com

D.sudo a2ensite 000-default &&sudo a2ensite blog.mytest.com