Apex domains cannot have CNAME records.
Question and response
Question
dig itjobmart.com. NS
Answer
itjobmart.com. 5 NS ns2.itjobmart.com.
itjobmart.com. 5 NS ns1.itjobmart.com.
Authority
The response has no authority records.
Additional
ns1.itjobmart.com. 5 A 170.62.109.73
ns2.itjobmart.com. 5 A 173.252.192.142
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0