R19. Suppose Host A wants to send a large file to Host B. The path from Host A to Host B has three links, of rates Ri 500 kbps, R2 2 Mbps, and R3 1 Mbps. a. Assuming no other traffic in the network, what is the throughput for the file transfer? b. Suppose the file is 4million bytes. Dividing the file size by the through- put, roughly how long will it take to transfer the file to Host B? c. Repeat (a) and (b), but now with R2 reduced to 100 kbps