The graph shows the price of a good compared to the quantity demanded and the quantity supplied. On this graph, what does the green arrow represent?

Answer:
an effective price ceiling set below equilibrium causing shortage.
Explanation:
Note that in the graph the green line indicates a price ceiling or benchmark that is lower (below) the equilibrium.
Remember, the shortage was due to the fact the companies (suppliers) reduced their supply following the normal law of supply, which results in desperate demand for the only available products.