Apex domains cannot have CNAME records.
Question and response
Question
dig pearson.savvis.net. NS
Answer
pearson.savvis.net. 1 NS ns6.savvis.net.
pearson.savvis.net. 1 NS ns2.savvis.net.
pearson.savvis.net. 1 NS ns5.savvis.net.
pearson.savvis.net. 1 NS ns4.savvis.net.
pearson.savvis.net. 1 NS ns3.savvis.net.
pearson.savvis.net. 1 NS ns1.savvis.net.
pearson.savvis.net. 1 NS ns6a.savvis.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0