Let's *assume* that this death is only certain IF you continue your current life style. If you were to change something you usually wouldn't change due to this new information, then knowing WHY you will die would be most beneficial. A good example would be "heart attack from poor diet + lack of exercise" you don't know when. where, or anything else...but it can be completely avoided if you just change your lifestyle. (Or avoid it if you are not doing that yet.)
They're all scary. I'd rather not. What if like someone said - it's a hospital bed or something, and you have to go to the hospital in your life multiple times for different things, even things like the birth of your own baby you will miss.
Why is scary, because what if it's of cancer or something. And you get diagnosed with Cancer, knowing you'll die. Or what if it's something simple like a Car Accident and now you never wanna ride in a car?
When is scariest because it could be tomorrow, and you have no way of preventing it. You could think "I'm not going to school today so I don't die" and not realize the place you died will be in your house and now you put death in your path.
None But I guess why. I wouldn't want to know when because I'd be counting down the days and freaking out with every passing minute. I wouldn't want to know where because I'd be freaking out every time I went there.