Audit evidence is generally considered "sufficient" when

a. it is appropriate.

b. it has been obtained from independent sources from outside the client entity.

c. it has the qualities of being reliable and relevant.

d. there is enough of it to afford a reasonable basis for an opinion on the financial statements.

e. it has been obtained by random selection.

Suppose that an auditor calculated the inventory turnover ratio for a client and saw that the current years ratio had fallen to 3, whereas the prior years ratio was 15. Which assertion would likely be called into question?

a. Authorization.

b. Cutoff.

c. Valuation.

d. Presentation.

e. Classification.