Douching is harmful to the vaginas walls. I would guess Spermicides.
I think A would be the correct answer. Your skin does not produce white blood cells, your body produces white blood cells and releases them into your blood system. Your skin does not also make T cells or antibodies. This all happens internally and they stay internal. Your body can absorb things like histamine, however I’m not sure how this would help to keep pathogens out of the body.
A proffessianl doctor, and dieting website.
The answer is b. amino acids
It depends on how much you use. But its all up to the parent. A lot of people say its fine with my research if you don't use much.