Suppose a UDP server creates a socket and starts listening for UDP packets at UDP port $5000$ at host interface having IP address IPS. a$.$ Suppose that a client A with IP address IPA and UDP port $2000$ sends a UDP packet having a destination address IPS and destination port $5000.$ What's the source and destination IP addresses and source and destination port numbers of this UDP packet? Assuming that the packet is delivered to the host where the server is running, would the UDP layer at the server deliver this packet to the UDP server? b$.$ Suppose now that a client B with IP address IPB and UDP port $8000$ sends a UDP packet having a destination address IPS and destination port $5000.$ What's the source and destination IP addresses and source and destination port numbers of this UDP packet? Assuming that the packet is delivered to the host where the server is running, would the UDP layer at the server deliver this packet to the UDP server? c$.$ If the UDP server wants to send a UDP packet to client A described in $($a$)$ what would be the source and destination IP addresses and source and destination port numbers of the packet? d$.$ If the UDP server wants to send a UDP packet to client B described in $($b$)$ what would be the source and destination IP addresses and source and destination port numbers of the packet?