Apex domains cannot have CNAME records.
Question and response
Question
dig viewpage.co. NS
Answer
viewpage.co. 5 NS ns-1611.awsdns-09.co.uk.
viewpage.co. 5 NS ns-748.awsdns-29.net.
viewpage.co. 5 NS ns-285.awsdns-35.com.
viewpage.co. 5 NS ns-1440.awsdns-52.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0