Which of the following statement is TRUE?

I. In a period of falling prices, Weighted Average process costing method (WA) will result in higher cost of goods sold as compared to FIFO process costing method

II. In a period of rising prices, WA process costing method will decrease tax payments as compared to FIFO process costing method

III. The operating income and the tax payment of a company are not affected by the method of process costing used by the company