Apex domains cannot have CNAME records.
Question and response
Question
dig bdo.com.pk. NS
Answer
bdo.com.pk. 4 NS ns1.cyber.net.pk.
bdo.com.pk. 4 NS ns5.cyber.net.pk.
bdo.com.pk. 4 NS csns8.cyber.net.pk.
Authority
The response has no authority records.
Additional
ns1.cyber.net.pk. 4 AAAA 2400:adce:4:4:0:0:0:4
csns8.cyber.net.pk. 4 AAAA 2001:4538:101:17:0:0:0:20
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0