Refer to the Accompanying Graph, Where S_d and D_d Are

Refer to the accompanying graph, where S_d and D_d are the domestic supply and demand curves for a product. The world price of the product is $6. If this market were closed to international trade, the total revenue that would go to domestic producers would be

A) $600, but only $240 if the domestic market were open to international trade.
B) $600, but only $120 if the domestic market were open to international trade.
C) $500, but only $240 if the domestic market were open to international trade.
D) $240, but only $120 if the domestic market were open to international trade.