I think the correct answer is B
Biodiversity boost the eco-system which essentially is the same reason we have plants without biodiversity we wouldn't have plants or trees. Therefore we wouldn't have oxygen so the more we kill the Eco-system the more our planet and life becomes more and more threatened therefore the more food supply and demand becomes less and less. Which basically leads to extinction. So biodiversity is also helpful for biodegradable products like plastic instead of foam. Essentially recycling basically saves our planet.
An antigen causes the body to make antibodies.
