Apex domains cannot have CNAME records.
Question and response
Question
dig it-prod-mgmt.aws.umd.edu. NS
Answer
it-prod-mgmt.aws.umd.edu. 5 NS ns-177.awsdns-22.com.
it-prod-mgmt.aws.umd.edu. 5 NS ns-1566.awsdns-03.co.uk.
it-prod-mgmt.aws.umd.edu. 5 NS ns-1170.awsdns-18.org.
it-prod-mgmt.aws.umd.edu. 5 NS ns-806.awsdns-36.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0