What is the main function of the treasury within government?

The primary function of the treasury within a government is to control all taxing and spending and manage the budget. This role is central to the economic operation of the government as it involves the collection of taxes and the allocation of funds to various government departments and services. The treasury develops fiscal policies and ensures that the government's financial matters are in order, which includes planning and executing the national budget.

Managing taxation and expenditure allows the treasury to influence the economy by determining how resources are distributed and what public services are funded. This includes everything from infrastructure projects to social services and education, making it a crucial component of government functioning. By ensuring efficient management of public funds, the treasury helps maintain economic stability and can respond to economic challenges.

The other options are more specialized functions that, while important, do not encompass the broad financial responsibilities that the treasury holds. Overseeing national defense, managing public health, or directing immigration policies are specific areas often handled by respective departments or ministries rather than the treasury itself.