Apex domains cannot have CNAME records.
Question and response
Question
dig careerbuilder.com. NS
Answer
careerbuilder.com. 4 NS misty.cbjobs.net.
careerbuilder.com. 4 NS brock.cbjobs.net.
Authority
The response has no authority records.
Additional
brock.cbjobs.net. 3 A 98.85.135.223
misty.cbjobs.net. 3 A 34.202.64.181
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0