The World Market for Newly Smelted Primary Aluminum (I

The world market for newly smelted primary aluminum (i.e., excluding scrap or recycled sources) recently experienced a period of rising inventories and falling prices. The Wall Street Journal reported that Russian smelter Rusal, the world’s largest aluminum producer, expected primary aluminum ingot prices would need to fall even further before worldwide inventory accumulation could stabilize. Suppose the demand for primary aluminum can be represented by the equation Qd = 124 − 0.025P (Qd is the monthly worldwide quantity demanded in millions of metric tons of new aluminum, P is the dollar price of new aluminum per ton) . Further suppose the world supply of aluminum is Qs = –50 + 0.025P (Qs is the monthly worldwide quantity supplied in millions of metric tons of new aluminum; P is the dollar price of new alu¬minum per ton) . On the axes provided below, sketch the world demand and supply curves for primary aluminum to help you answer the next three questions

-At the time of Rusal's concern,primary aluminum prices were relatively high at $4,200 per ton.At this price,calculate the monthly rate of inventory growth in the global aluminum market using the given demand and supply equations for the world aluminum market.

A) Inventories would be growing at a rate of 36 million metric tons per month.
B) Inventories would be growing at a rate of 55 million metric tons per month.
C) Inventories would be falling at a rate of 19 million metric tons per month.
D) Inventories would be falling at a rate of 37 million metric tons per month.