Identify which basic principle of accounting is best described in each item below. a. Norfolk Southern Corporation reports revenue in its income statement when the performance oblization is satisfied instead of when the cash is collected. b. Yahoo! recognizes depreciation expense for a machine over the 2 -vear period during which that machine helps the company earn revenue. c. Oracle Corporation reports information about pending lawnits in the notes to its financial statements. d. Gap, Inc. reports land on its balance sheet at the amount paid to acquire it, even though the estimated fair value is greater.