Suppose a, b, and c all make their first carrier sense, as part of an attempt to transmit, while a fourth station d is transmitting. draw a timeline showing one possible sequence of transmissions, attempts, collisions, and exponential backoff choices. your timeline should also meet the following criteria: i. initial transmission attempts should be in the order a, b, c but successful transmissions should be in the order c, b, a, and ii. there should be at least four collisions.