That's false. Animals have mitochondria too. It's responsible for cellular respiration, not photosynthesis.
20 protons
20 electrons ( as much elctrons as protons because there has to be same positive and negative to have a neutral atom)
And the number of neutrons depends of the mass number but in that case, I think that it's a Calcium atom (Ca) and so there are 20 netrons.
B----------- oxide is the correct answer
PH = -log10 [H+]. So anwer 2 pH
