According to US-CERT; if an agency is unable to successfully mitigate a DOS attack it must be reported within:
A . One (1) hour of discovery/detection if the successful attack is still ongoing
B . Two (2) hours of discovery/detection if the successful attack is still ongoing
C . Three (3) hours of discovery/detection if the successful attack is still ongoing
D . Four (4) hours of discovery/detection if the successful attack is still ongoing
Answer: B