Classify the following evident items by source (direct knowledge, external, and so on), rank them in order of reliability, and explain the reasons for your ranking.

a. Amounts shown on monthly statements from creditors

b. Amounts shown on "paid on account" in the accounts payable register

c. Amount of "discounts lost expense" computed by the auditor from unaudited supporting documents

d. Amounts shown in letters received directly from creditors

2. Classify the following evident items by source (direct knowledge, external, and so on), rank them in order of reliability, and explain the reasons for your ranking.

a. Amounts shown on a letter received directly from an independent bond trustee

b. Amounts obtained from minutes of board of directors' meetings

c. Auditors' recalculation of bond interest and amortized cost when remaining term and status of bond are audited

d. Amounts shown on cancelled cheque.