书上明确表示 GAAP下interest paid,received,dividends received 都是operating的，只有dividends paid 是financing的

但是做的题中如mock  morning 54中提到interest expense是finance的，

而且volumn2 里Exam2 Afternoon 169说 interest expense和interest income都是non-operating 的

这是为什么呢？

附54题

54. Assume U.S. GAAP (generally accepted accounting principles) applies unless otherwise noted.
For the most recent year a manufacturing company reports the following items on their income statement:

 Interest expense $62,500

Loss on disposal of fixed assets $50,000

Realized gain on sale of available-for-sale securities $17,750

Which of the items is classified as an operating item in the company’s income statement?
A. Interest expense.
B. Loss on disposal of fixed assets.
C. Realized gain on sale of available-for-sale securities.