Comment on whether of each of the following examples of audit evidence should be considered "highly competent" evidence or "less competent" evidence. Explain each of your answers.

a. Copies of clients sales invoices.

b. Auditors independent computation of earnings per share.

c. Paid checks returned with a bank statement.

d. Response from customer of client addressed to auditors office confirming amount owed to client at balance sheet date.

e. Representation letter signed by controller of client company stating that all liabilities of which she has knowledge are reflected in the companys accounts.