mysql数据库地址为localhost,登录名为root,登录密码为12346,要连接的数据库名为yzdata
A. $con=mysqli_connect('yzdata','root','123456','localhost');
B. $con=mysqli_connect('localhost','root','123456','yzdata');
C. $con=mysqli_connect('localhost','123456','root','yzdata');
D. $con=mysqli_connect('localhost','root','yzdata','123456');