Apex domains cannot have CNAME records.
Question and response
Question
dig 159d.com. NS
Answer
159d.com. 5 NS ns-1787.awsdns-31.co.uk.
159d.com. 5 NS ns-995.awsdns-60.net.
159d.com. 5 NS ns-180.awsdns-22.com.
159d.com. 5 NS ns-1663.awsdns-15.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0