Well you see unicellular organisms are very unique in the fact that they live all on their own and move around with a flagellum or little motor, but to the point unicellular organisms carry out essentially every function in life and they must in order to simply survive. So it's most likely D.
Because the electrons in this ionic compound arent free to move and so cannot carry charge. For an iconic compound to conduct electricity it must be a liquid, either in a molten form or dissolved in water.