2. (45 pts] Explain how each of the mechanisms A, B an C for routing data within a network operate, and explain how (and whether) a network based on each one deals with these: i. Determining a loop-free path from sender to receiver ii. Choosing between multiple paths from sender to receiver iii. Changes in topology iv. Communication links with widely differing characteristics Autonomous System transit policy V. A. Local area networks using the spanning tree algorithm B. Wide area networks using link-state routing C. Wide area networks using BGP