You are the network administrator for The network consists of a<br /> single DNS domain named.<br /> You replace a UNIX server with a Windows Server 2003 computer named<br /> TestKing1.<br /> TestKing1 is the DNS server and start authority (SOA) for testking.com. A UNIX<br /> server named TestKing2 is the mail server for testking.com.<br /> You receive reports that Internet users cannot send e-mail to the testking.com<br /> domain. The host addresses are shown in the following window.<br /> <img src="https://nimg.ppkao.com/2018-07/yuanhao/2018073014460495183.jpg?sign=9a599d76002a147d3d01887576efd828&t=62d0f1b0" /><br /> You need to ensure that Internet users can send e-mail to the testking.com domain.<br /> What should you do?()
A、Add an _smtp service locator (SRV) DNS record for TestKing2.
B、Add a mail exchange (MX) DNS record for TestKing2.
C、Add an alias (CNAME) record for mail.testking.com.
D、Enable the SMTP service on TestKing1.