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 choice. your timeline should also meet following critetria: (i) initial transmission attempts should be in other a, b,c but successful transmission should be in the other c, b,a, and (ii)there should be at least four collisions.