Answer: D. The Chief of Staff
Explanation:
The White House Chief of staff is not a position that is chosen lightly. This person usually commands the highest respect from the President because they are the closest advisor the President has.
The Chief of Staff is in constant communication and presence with the President and even controls the appointments to see the President to manage the President's time.
It is very important to note that even though the President has a slew of Advisors, they are usually focused on one area of governance. The Chief of Staff is focused on all of them. If you are familiar with the character of Seth Grayson in House of Cards then you have a clearer picture.
For these reasons, the Chief of Staff would be the best source on a President’s personal thoughts.
