The answers B we're using them faster than they can form
Most models can't incorporate all the details of complex natural phenomena. For example, when measuring distances around the Earth it's convenient to model the Earth as a sphere, but this doesn't incorporate variations in distance because of mountain ranges, valleys and other topological features the traveler must traverse. Incorporating these additional details would make the model too complex for easy use. Since models must be simple enough that you can use them to make predictions, they often leave out some of the details.
ALSO.
The conformation of molecules are based on probability. It fails to take into account the electronegativity of individual atoms. And it is ineffective in showing inorganic interactions with metals and such.
The garden plants and snails stay balanced as they are still being eaten. However, if the cat is removed, the birds will overpopulate and then the snail would be eaten and decrease faster which gives garden plants an increase in population due to the decrease in snails. Hope this helps!