Every time that she stopped, the value of the speed is 0, the speed limit is the maximum represented in the graph and when she travels at this speed for a while the graph is a horizontal line.
So she starts at 0, then increases her speed until a limit then she drives at this speed for a while which is represented by a horizontal line. then, she has to slow to a stop, which means she goes back to 0, later increases her speed until the limit, drives a while until she finds a stop sign, represented by a horizontal line, and then goes to 0.
In conclusion, the graph that represents the journy is the fourth graph.