Number of protons - 3
number of neutrons - 4
number of electrons - 3
Can be a number of things, rain fall quota, climate, population, vegetation..any of those.
It results in change of the phase temperature and heat
Among the given choices, the only positive effect that may be thought off with the increase in level of CO2 in the atmosphere is the increase of plant growth. Carbon dioxide is an essential compound in the photosynthesis of plants. Therefore, the answer should be letter C.