Answer (c) is correct because an audit program sets forth in detail the audit procedures that are necessary to accomplish the objectives of the audit.
Answer (a) is incorrect because audit programs address topics beyond selecting material transactions and this is not their primary focus.
Answer (b) is incorrect because a program may include numerous substantive tests to be performed prior to the balance sheet date.
Answer (d) is incorrect because immaterial accounts often are not tested and because tests of transactions, tests of balances, and analytical procedures are used to test account balances; account balances are not directly tested through tests of controls.