The correct answer is E.
Executive privilege is the power of the President of the United States to refuse to comply with demands for information like congressional subpoenas or Freedom of Information Act requests.
This privilege is used to keep private some conversations the President has with his trusted advisers or during international meetings and discussions.
This privilege can not be used as a cover-up for wrongdoings. President Nixon was ordered to hand in some suspicious tapes for judicial review, despite his executive privilege.
Executive privilege is not mentioned in the Constitution but it is seen as a tool of separation and balance of power.