Your answer would definitely be D - Mitochondria. Mitochondria is the organelle that supplies all the energy for a cell. Hope I was helpful, have a good day! 8)
I'll say that it is +1 since hydrogen is desperate to lose an electron to fulfill the octave rule (that the molecules want to gain 8 electrons and if they can't do it, they want to lose all their electron). Electron is - so if it lose a electron, it becomes +.
Hopefully this helps.
PS. I'm not certain of my answer but it is logical.
