It is defiantly not a, because only part of the park was burnt. It wouldn't be c, because fire does not cause seeds to fly in. I would say B
Dress themselves because like that they are taking care of their physical body and keeping it nice and healthy
It gets polluted from fertilizers or any spilled chemicals. And those chemicals get obsorbed into the ground. And the gravity pushes them deeper in the soil, till it reaches the underground water (or aquifer)
