Apex domains cannot have CNAME records.
Question and response
Question
dig tuart.netdesignhost.com. NS
Answer
tuart.netdesignhost.com. 5 NS ns1.netdesignhost.com.
tuart.netdesignhost.com. 5 NS ns2.netdesignhost.com.
Authority
The response has no authority records.
Additional
ns1.netdesignhost.com. 2 A 150.95.20.60
ns2.netdesignhost.com. 2 A 150.95.20.180
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0