Apex domains cannot have CNAME records.
Question and response
Question
dig egov.com. NS
Answer
egov.com. 4 NS glns-1.cdc.nicusa.com.
egov.com. 4 NS ns2.nicusa.com.
egov.com. 4 NS ns3.nicusa.com.
egov.com. 4 NS glns-4.cdc.nicusa.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0