Apex domains cannot have CNAME records.
Question and response
Question
dig oproser.edu.do. NS
Answer
oproser.edu.do. 1 NS dns2.midominio.do.
oproser.edu.do. 1 NS aajm1167110.venus.orderbox-dns.com.
oproser.edu.do. 1 NS dns1.midominio.do.
oproser.edu.do. 1 NS dns3.midominio.do.
oproser.edu.do. 1 NS dns4.midominio.do.
oproser.edu.do. 1 NS aajm1167110.mars.orderbox-dns.com.
oproser.edu.do. 1 NS aajm1167110.mercury.orderbox-dns.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0