Which of the following is not an instrument for controlling public expenditure?

The instrument that is not for controlling public expenditure is a "memorandum". A constitution is a document that outlines the fundamental principles, rules, and regulations that govern a country, including its financial management. Financial regulations provide guidelines and procedures for the proper management of public funds. A budget is a financial plan that outlines expected revenue and expenses for a specific period and helps control government spending. However, a memorandum is a written message or communication used for various purposes, such as expressing thoughts, sharing information, or making requests, and is not an instrument used for controlling public expenditure.