The cell would never be able to be in a the stage of the cell cycle where it is just doing its job (which would depend on its specialization). The other phases are all dedicated to replicating (dividing) the cell from one to two cells. Interphase allows the cell time to just preform the job (function) it was created to do.
Your breathing is likely to speed up when your cells need more energy. Why? Well, faster breathing is likely to occur when your cells need more energy because doing things that force your muscles to work harder cause sweat glands often (which originates from the endocrine system), and to recuperate energy, your breathing rate increases so that more energy is circulated into your body.
Your final answer: The answer is D.
Because just the right amount of nitrogen and phosphorus makes the soil grow really good. But too much will kill the soil.