The main function of the executive branch is to. carry out and enforce laws and policies. write and pass new national legislation. increase the size of the bureaucracy. select who will serve as president. examples of how congress oversees the power of the executive branch is its power to. a) approve presidential appointments and conduct investigations. b) create regulations that only apply to official executive offices. c) sign the president's policies into law and enforce regulations. d) impeach executive officials for creating too much red tape