Apex domains cannot have CNAME records.
Question and response
Question
dig couponsroo.com. NS
Answer
couponsroo.com. 2 NS ns2.couponsroo.com.
couponsroo.com. 2 NS ns1.couponsroo.com.
Authority
The response has no authority records.
Additional
ns1.couponsroo.com. 2 A 170.130.202.46
ns2.couponsroo.com. 2 A 173.44.158.38
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0