Which of the following descriptions of smart DNS is incorrect?

Which of the following descriptions of smart DNS is incorrect?
A . By configuring the smart DNS function, the firewall can intelligently modify the resolution address in the DNS response message so that the user can obtain the most appropriate resolution address, that is, an address that belongs to the same ISP network as the user.
B . Intelligent DNS supports weighted polling to achieve link load balancing
C . Smart DNS does not need to be combined with other technologies and can be used alone
D . Smart DNS is divided into two scenarios: single-server smart DNS and multi-server smart DNS.

Answer: C