In the excerpt the "long road" symbolizes the bluesman's personal growth and life journey. He talks about how the road "has curved through trouble and joy." These curves are the different emotions and events that the bluesman has experience in his life. Since the excerpt talks about both trouble and joy, any option can be eliminated that speaks to only one of those emotions...this eliminates all the others. It can also be noted that a road is a common symbol for the path a person's life takes. Frost talks about a road that splits in one of his poems to show that the road less traveled is better than the one everyone takes. We also see this in popular songs and movies as well.
