Which of the following statements concerning the management discussion and analysis (MD&A) of a company's financial condition is true?

1. I. It should cover the financial statements and other statistical data for the most recent three-year time span.
2. II. It should make year-to-year comparisons of material changes in the line items.
3. III. Management need not explain the cause(s) of the material changes.
4. IV. Disclosure of immaterial off-balance sheet transactions, arrangements, and obligations is required in each annual and each quarterly report.