Apex domains cannot have CNAME records.
Question and response
Question
dig pr.afilias-nst.org. NS
Answer
pr.afilias-nst.org. 5 NS b0.pr.afilias-nst.org.
pr.afilias-nst.org. 5 NS d0.pr.afilias-nst.org.
pr.afilias-nst.org. 5 NS c0.pr.afilias-nst.info.
pr.afilias-nst.org. 5 NS a2.pr.afilias-nst.info.
pr.afilias-nst.org. 5 NS a0.pr.afilias-nst.info.
pr.afilias-nst.org. 5 NS b2.pr.afilias-nst.org.
Authority
The response has no authority records.
Additional
a0.pr.afilias-nst.info. 5 A 199.254.59.17
a2.pr.afilias-nst.info. 5 A 199.249.116.17
b0.pr.afilias-nst.org. 5 A 199.254.60.17
b2.pr.afilias-nst.org. 5 A 199.249.124.17
c0.pr.afilias-nst.info. 5 A 199.254.61.17
d0.pr.afilias-nst.org. 5 A 199.254.62.17
a0.pr.afilias-nst.info. 5 AAAA 2001:500:25:0:0:0:0:17
a2.pr.afilias-nst.info. 5 AAAA 2001:500:44:0:0:0:0:17
b0.pr.afilias-nst.org. 5 AAAA 2001:500:26:0:0:0:0:17
b2.pr.afilias-nst.org. 5 AAAA 2001:500:4c:0:0:0:0:17
c0.pr.afilias-nst.info. 5 AAAA 2001:500:27:0:0:0:0:17
d0.pr.afilias-nst.org. 5 AAAA 2001:500:28:0:0:0:0:17
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0