Apex domains cannot have CNAME records.
Question and response
Question
dig bluecrossflorida.net. NS
Answer
bluecrossflorida.net. 2 NS dns1.bcbsfl.com.
bluecrossflorida.net. 2 NS dns2.bcbsfl.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0