Answer: c. economic regulation because they regulate only the activities of banks.
Explanation:
Economic Regulation refers to rules, regulations and policies that are established by a Governmental or Independent Adminstrative agency with the aim being to monitor the entrance of new firms as well as the activities of existing firms in an industry including the financial industry. They help protect the industry through their actions and are thus very important.
A very important example of such an organization is the Office of the Comptroller of the Currency. They have the mandate of regulating all national Banks including foreign Banks as well. As the regulator of such an industry and going by the definition of an Economic regulation, the regulation they apply is Economic in nature to ensure that the banks behave in such a way that will not be detrimental to the industry and the Economy.