Which of the Following Statements Concerning IFRS and U

Which of the following statements concerning IFRS and U.S. GAAP is true?

A) IFRS permits revaluation of all intangible assets, whereas U.S. GAAP prohibits revaluation of intangible assets.
B) Gains on exchange of assets when the exchange has commercial substance are recognized under both IFRS and U.S. GAAP.
C) Changes in depreciation method under IFRS are reported in current and future periods, under U.S. GAAP such changes are treated as prior period adjustments.
D) All of these answer choices are correct.