Platinum is a relatively rare metal vital to a wide variety of industries. Xagor Corporation, a major producer of platinum, has its production plant in a country that will soon begin imposing an export tax on platinum sold and shipped to customers abroad. As a consequence, the price of platinum on the world market is bound to rise. Which of the following, if true, tends to confirm the conclusion above? ['New deposits of platinum have been found in the country in which Xagor has its production plant.', 'The largest of the industries that depend on platinum reported a drop in sales last month.', 'An inexpensive substitute for platinum has been developed and will be available to industry for the first time this month.', 'The producers of platinum in other countries taken together cannot supply enough platinum to meet worldwide demand.']