A. 3
From 0 to 6, a solution is acidic. 7 is neutral and from 8 to 14.. is basic
This is more to do with Bioaccumulation of mercury, where the mercury is absorbed into the issue of animals, and so animals higher in the food chain consume a lot of tissue matter hence increasing mercury content in their system.
C magnetic repulsion, forgive me if I’m wrong
Photosynthesis takes place in the chloroplasts, that is why the chloroplasts is green. The function of this organelles is to create energy into sugar from the sunlight.