A company has a primary DNS server at address 192.168.10.53 and a secondary server at
192.168.20.53. An administrator wants to secure a company by only allowing secure zone
transfers to the secondary server. Which of the following should appear in the primary DNS
configuration file to accomplish this?

A.
key company-key.{
algorithm hmac-rc4;
secret “Hdue8du9jdknkhdoLksdlkeYEIks83K=”;
};
allow transfer { 192.168.20.53; }

B.
key company-key.{
algorithm hmac-md5;
secret “Hdue8du9jdknkhdoLksdlkeYEIks83K=”;
};
allow transfer { 192.168.10.53; }

C.
key company-key.{
algorithm hmac-md5;
secret “Hdue8du9jdknkhdoLksdlkeYEIks83K=”;
};
allow transfer { 192.168.20.53; }

D.
key company-key.{
algorithm hmac-rc4;
secret “Hdue8du9jdknkhdoLksdlkeYEIks83K=”;
};
allow transfer { 192.168.10.53; }