Which one of the following subjects does not fall under the control of

Which one of the following subjects does not fall under the control of Department of Expenditure ?

Financial rules and regulations and delegation of financial powers
Indian Audit and Accounts Department
Policy relating to exchange rates of Rupee
Matters relating to the Controller General of Accounts
This question was previously asked in
UPSC SO-Steno – 2018
Policy relating to exchange rates of Rupee does not fall under the control of the Department of Expenditure. This subject is primarily handled by the Department of Economic Affairs (DEA) within the Ministry of Finance, in consultation with the Reserve Bank of India (RBI).
The Department of Expenditure focuses on managing public expenditure, financial rules, internal audit, and matters related to the Controller General of Accounts. Exchange rate policy is a macroeconomic policy tool that falls under the purview of the Department of Economic Affairs.
Options A, B (matters relating to CAG other than personnel/admin of IA&AD), and D relate directly to the functions and oversight responsibilities of the Department of Expenditure concerning government finance and accounting. While the Comptroller and Auditor General (CAG) heading the Indian Audit and Accounts Department (IA&AD) is an independent constitutional authority, the Department of Expenditure does handle certain administrative matters relating to the CAG, as per the Allocation of Business Rules, unlike the policy on exchange rates which is entirely under DEA.