The correct option is A Petty cash book
The imprest system is an accounting system for paying out and subsequently replenishing petty cash. A cashier maintaining petty cash is given a definite sum of money in the beginning of a period and is reimbursed for payments made at the end of the period. Thus, he will have again the fixed amount in the beginning of the new period. This system is known as the imprest system of petty cash book.