The correct option is D Dependant on nature of business
Petty cash book - This is used to record petty expenses like postage. cartage. printing and stationery etc in the day to day business activities.
In big organisation, it is not possible to maintain petty expenses for main cashier. In small organisation the number of petty Expenses is less so such a book can be maintained by cashier. Maintaining such a book is not compulsory.
So, maintaining petty cash book is dependent on nature of business.