The correct command to retrieve mail server records for a domain using nslookup is nslookup -query=mx example.com. The -query=mx option specifies that the Mail Exchanger (MX) records should be retrieved, which are used for email routing. Understanding the correct syntax and options for nslookup commands is essential in diagnosing DNS issues effectively. \n\nThe incorrect answers provided either use wrong query types or misunderstand the function of nslookup: \n- -query=a retrieves address records (A records), which is incorrect as the scenario specifies a check for mail server records (MX records). \n- -type=soa retrieves the Start of Authority (SOA) record, which is useful for information about DNS zone transfers and not email.\n- example.com -mx lacks the proper nslookup command structure and incorrectly places options.