Computer Networking course - Network delay and throughput

Consider the simple network shown in the figure. The source and destination nodes are interconnected with N optical fiber links. The source host segments a long message into 3 smaller packets and sends the packets into the network. The links' transmission rates and lengths are(R_1, R_2, ..., R_N) and (d_1, d_2, ..., d_N), respectively. The figure's timing is drawn to scale. a. Explain which link has the highest transmission bit rate and which one has the lowest transmission bit rate. b. Explain which link has the longest propagation distance