Answer:
A. To oversee the operation of executive departments
Step-by-step explanation:
The executive departments consist of several organizations which were created to execute the government programs that are proposed by the legislative branch.
Currently, United States have 15 Executive departments. It is impossible for president to personally lead each department alone. This was the reason for the cabinet members.
The president personally select each cabinet members based on a specific skill sets or other criteria's so they can run each departments on the president's behalf.