Final answer:
The FASB and IASB collaboratively worked on revenue recognition, resulting in the FASB issuing an Accounting Standards Update for U.S. GAAP and the IASB issuing IFRS 15. This means that both statements in the question are correct, and answer c (both a and b) is the best description of their collaboration. Option a.
Step-by-step explanation:
The collaboration between the Financial Accounting Standards Board (FASB) and the International Accounting Standards Board (IASB) on revenue recognition can best be described as both organizations working together to improve and converge their standards. This resulted in the issuance of a converged standard, with FASB issuing an Accounting Standards Update (ASU) applicable to companies reporting under U.S. GAAP, while the IASB issued International Financial Reporting Standards (IFRS) 15, titled 'Revenue from Contracts with Customers'.
The joint effort aimed to provide a robust framework for addressing revenue recognition issues, leading to increased comparability and reducing the complexity in revenue recognition practices across global markets. Answer c. both a and b is correct as it reflects both the joint effort (part b) and the actual issuance of the standard by FASB (part a).