Why is it difficult to compare IFRS15/ASC606, Revenue, to U.S. GAAP?

A. The IASB definition of revenue is very complicated, whereas the definition of revenue under U.S. GAAP is straightforward.

B. Revenue is not defined under U.S. GAAP.

C. There is no single standard in U.S. GAAP that deals solely with revenue.

D. Under U.S. GAAP, revenue is defined in terms of cash, whereas IAS 18 defines revenue in terms of a variety of resources.