CSMA method is used, please provide solution step by step

Consider the figure below, which shows the arrival of 12 messages for transmission at different multiple access wireless nodes at times t=0.1,0.8,0.9,1.2,1.9,2.7,3.1,3.5,3.6,4.4,4.5,4.8 and each transmission requires exactly one time unit. QUESTION 1 OF 2 Suppose all nodes are implementing Carrier Sense Multiple Access (CSMA), but without collision detection. Suppose that the time from when a message transmission begins until it is beginning to be received at other nodes is 0.4 time units. (Thus if a node begins transmitting a message at t=2.0 and transmits that message until t=3.0, then any node performing carrier sensing in the interval [2.4,3.4] will sense the channel busy.) For each message, indicate the time at which each message transmission begins, or indicate that message transmission does not begin due to a channel that is sensed busy when that message arrives. Separate each value with a comma and no spaces, and if the channel is sensed busy, substitute it with 's