Refer to the exhibit. Which statement is true about the configuration？（）

• A、Hosts belonging to DHCP pool 1 and pool 2 will retain their IP settings for 30 hours before theymust renew
• B、Hosts will receive IP settings from pool 1 until the addresses run out， and then hosts will receivethe settings from pool 2
• C、Hosts in the 10.10.20.0/24 subnet will use 10.10.20.50 as its DNS server
• D、DHCP pool 0 needs to have the ip dhcp excluded-address command to exclude the defaultrouter and DNS servers