The answer to this is law
Type a individuals are more likely to experience high levels of stress.
You should be able to get the answers from this chart ;)
The framers planned for continuity during a national crisis by creating the Presidential Line of Succession.
So far, this has only been applied when the President is killed and the Vice President takes their place.
But the line goes much deeper.
Attached is the current line of succession under President Trump.
In January, Paul Ryan will be replaced by Speaker Nancy Pelosi (D).