Question：Which one of the following provides evidence that an item of expenditure on petty cash has been approved or authorised?
　　A. Record of the transaction in the petty cash book
　　B. Receipt for the expense
　　C. Transfer of cash from the bank account into petty cash
　　D. Petty cash voucher
　　The correct answer is: Petty cash voucher.
　　解析：The petty cash voucher is a record that cash has been issued for an approved item of expense. The receipt is evidence of the amount of the expense. The petty cash book is used to record the transaction in the book-keeping system.