The correct answer is B) the Presidential power has grown.
The power of the President has changed over the years in that the Presidential power has grown.
Times have changed and the needs of the United States also. International circumstances of the threat of terrorism have changed the political power of the executive branch in the US. Indeed, the system of checks and balances between the branches of governments is a good system but the executive had to make decisions to act promptly and do not wait until Congress decides on an issue.
This is seen even more in these days when the present administration has a President acting differently than its ancestors, creating so much controversy in the nation.