Audit Evidence Has Two Primary Qualities for the Auditor; Relevance

Audit evidence has two primary qualities for the auditor; relevance and reliability.Given the choices below, which provides the auditor with the most reliable audit evidence?

A) General ledger account balances
B) Confirmation of accounts receivable balance received from a customer
C) Internal memo explaining the issuance of a credit memo
D) Copy of month-end adjusting entries