The default-router is the default gateway, which in this case is the primary IP address of interface c4/0 (option3). Option 7 is the Log server dhcp option. Option 4 is the ToD server ip address (primary ip address of interface c4/0). Option 2 is the time offset option for G...
The network provides the IP address and the subnet mask (DHCP option 1). The bootfile provides the boot file name which in this case is platinum.cm. The next-server command specifies the TFTP server IP address (in this case is the primary ip address in the interfa...