Apex domains cannot have CNAME records.
Question and response
Question
dig antietamcable.com. NS
Answer
antietamcable.com. 4 NS ns5.myactv.net.
antietamcable.com. 4 NS ns1.myactv.net.
Authority
The response has no authority records.
Additional
ns1.myactv.net. 4 A 24.89.0.57
ns5.myactv.net. 4 A 24.89.0.58
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0