What is the DHCP DISCOVER message's source and destination IP and MAC addresses, and why are these addresses unusual?

• A.DHCPDISCOVER: Source IP = 0.0.0.0 (client has no IP yet); Destination IP = 255.255.255.255 (limited broadcast); Source MAC = client's MAC address; Destination MAC = FF:FF:FF:FF:FF:FF (Ethernet broadcast). These are unusual: 0.0.0.0 is used as source because the client has no assigned IP; Ethernet and IP broadcast addresses ensure all devices on the local segment receive the message.
• B.DHCPDISCOVER source IP = 169.254.x.x (APIPA); destination = the known DHCP server IP.
• C.DHCPDISCOVER source MAC = 00:00:00:00:00:00 because the client has not yet been assigned a MAC address.
• D.DHCPDISCOVER uses 127.0.0.1 as source IP so the server can identify local network clients.