ALL OF THIS IS MY PERSPECTIVE/THEORY, NOT FACT NOR AM I STATING IT AS SO
Present.
Also, I don't like the time machine threads. If you used a time machine, the fact that you even traveled back makes way more than a tiny difference.
Second, you create a new timeline for every action anything makes. There are so many dimensions it hurts.
Third, if you go back and kill anyone, you've just spawned a new timeline. You'll still be alive, and your parent will be dead. You won't be alive as a true copy in the timeline you're in, yes, but you'll still exist as if you always had in the one you have reached. The only problem this causes is that you can't travel back to your original point in time. But it won't matter anyway, likewise.
So since I can't do anything past the point of travel, I decide stay in the present.
But since that time machine had already been invented, things already would've been changed.