A Windows host is started for the first time.

When a Windows host first boots up and does not have an IP address, it sends a DHCP Discover message to find a DHCP server.

The source IP address of this packet is 0.0.0.0, meaning the host does not yet have an assigned IP.

The destination IP address is 255.255.255.255, which is a broadcast address.

Option A (Incorrect - 127.0.0.1): This is the loopback address, used for internal testing.

Option B (Incorrect - 169.254.2.33): This belongs to the APIPA (Automatic Private IP Addressing) range, assigned when a DHCP server is unavailable.

Option C (Correct - 0.0.0.0): The correct source IP for the initial DHCP Discover packet.

Option D (Incorrect - 255.255.255.255): This is used as the destination IP for broadcasting, not the source.

Thus, the correct answer is C.