Which of these statements is correct regarding SSO and Cisco NSF？（）

• A、 Utilizing Cisco NSF in Layer 2 environments can reduce outages to one to three seconds.
• B、 Utilizing SSO in Layer 3 environments can reduce outages to one to three seconds.
• C、 Distribution switches are single points of failure causing outages for the end devices.
• D、 Utilizing Cisco NSF and SSO in a Layer 2 environment can reduce outages to less than onesecond.
• E、 NSF and SSO with redundant supervisors have the most impact on outages at the accesslayer.