Apex domains cannot have CNAME records.
Question and response
Question
dig pdpa.edu.do. NS
Answer
pdpa.edu.do. 5 NS ns1.webmediard.net.
pdpa.edu.do. 5 NS ns2.webmediard.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0