Select the location that has the highest precedence when the nfsmapid daemon searches for a domain name.

Your organization uses NFS to share data from Oracle Solaris servers to Oracle Solaris clients.
For the nfsmapid daemon to work properly the client and server must be on the same domain.
Select the location that has the highest precedence when the nfsmapid daemon searches for a
domain name.

A.
the nfsmapid_domain parameter in the mapid SMF service.

B.
the nfsmapid_domain parameter in the /etc/default/nfs file

C.
the domain name in the /etc/default/domainname file, if it exists.

D.
a_nfsv4idmapdomain TXT record found by the configured domain name servers

Explanation:
See 1 below.
Precedence Rules
For nfsmapid to work properly, NFS version 4 clients and servers must have the same domain. To
ensure matching NFS version 4 domains, nfsmapid follows these strict precedence rules:
1. The daemon first checks the SMF repository for a value that has been assigned to the
nfsmapid_domain parameter. If a value is found, the assigned value takes precedence over any
other settings. The assigned value is appended to the outbound attribute strings and is compared
against inbound attribute strings.
2. If no value has been assigned to nfsmapid_domain, then the daemon checks for a domain
name from a DNS TXT RR. nfsmapid relies on directives in the /etc/resolv.conf file that are used
by the set of routines in the resolver. The resolver searches through the configured DNS servers
for the _nfsv4idmapdomain TXT RR.
3. If no DNS TXT record is configured to provide a domain name, then the nfsmapid daemon uses
the value specified by the domain or search directive in the /etc/resolv.conf file, with the directive
specified last taking precedence.
4. If the /etc/resolv.conf file does not exist, nfsmapid obtains the NFS version 4 domain name by
following the behavior of the domainname command. Specifically, if the /etc/defaultdomain file
exists, nfsmapid uses the contents of that file for the NFS version 4 domain. If the
/etc/defaultdomain file does not exist, nfsmapid uses the domain name that is provided by the
network’s configured naming service.