With reference to evidence, what extent of evidence is required as a basis for the unmodified opinion?

Question:

With reference to evidence, what extent of evidence is required as a basis for the unmodified opinion? For an adverse opinion? For an opinion qualified for departure?

GAAP
Generally Accepted Accounting Principles (GAAP) is the accounting standard adopted by the U.S. Securities and Exchange Commission (SEC). While the SEC previously stated that it intends to move from U.S. GAAP to the International Financial Reporting Standards (IFRS), the...