The other answers are B C and E
A, B and C are the events that will cause an ecological disturbance.
Rationale:
A. Introduction of a new species: When a new specie is introduced, it increases the competition in ecosystem with the native species for food, water, space and shelter. This affects the reproductive success of the native species and thus the dynamics of ecosystem.
B. Climate change: Climate change is different from a simple change of weather. The best example would be of Antarctica where the ice is melting fast due to the global warming. The native species find it harder to adapt to the warm temperatures.
C. Late spring snowstorm: Spring is the season where the plants grow and animals shed their fur. When snowstorms occur in this season they harm these plants and animals that live there.
I'm pretty sure it's polyploidy
An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials (gravel, sand, or silt). Groundwater can be extracted using a water well.
