Answer:
c. 2
Explanation:
As the routers are only involved with the process of finding the best route to reach an IP address (the destination hosts), they don't look at the IP Datagram payload (which includes the transport protocol header), only to IP header.
So, the only transport processes that "talk"each other, are the one on the source host (defining TCP or UDP source port/s, and the other on the destination host (defining TCP or UDP destination port/s), so two applications (or more) in both machines can exchange data.
