Which statement best describes the differences between Cisco SMARTnet and Cisco SMARTnet onsite？（）

• A、 CiscoSMARTnet Onsite includes all of the elements of Cisco SMARTnet， with the additional provision of onsite technician to perform parts replacement
• B、 CiscoSMARTnet Onsite is primary attractive to customers who do not need to replace their hardware immediately， but would still like an onsite technician to install and replace hardware
• C、 CiscoSMARTnet Onsite includes certification classes and live network consulting at the customer site
• D、 CiscoSMARTnet Onsite provides network monitoring for small-to-medium sized businesses and provides onsite technical resources when hardware problems are detected