mx.whoville.org has no NS records.
NS records for this zone are defined at whoville.org.
NS records for this zone are defined at whoville.org.
Question and response
Question
dig mx.whoville.org. NS
Answer
The response has no answer records.
Authority
whoville.org. 3600 SOA dns.whoville.org. hostmaster.whoville.org. 1695353555 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0