Explain how the vice president can become president due to a disability.

if the president gets hurt or dies the vice president steps in if it's an injury until the injury heals and then when the president is good he will go back to being the president but if the president if the president dies he will become president for the rest of the term for example if their is 2 years left for the presidents term the vice president will complete that. Also, if let's say the president breaks his ankle the vice president steps up so the actual president could focus on getting better and everything

are there any options?