This elementary problem begins to explore propagation delay and transmission delay, two central concepts in data networking. Consider two hosts, A and B$,$ connected by a single link of rate R bps$.$ Suppose that the two hosts are separated by m meters, and suppose the propagation speed along the link is s meters$/$sec$.$ Host A is to send a packet of size L bits to Host B$.$

a$.$ Express the propagation delay, dprop, in terms of m and s$.$