Hi
The answer is called a mutation
The tadpole would die out. Which would cause the sudden decrease I duck and frog.
This could be a mutualism rather than a commensal relationship because when<span> "cleaner fish" consume parasites and mucus from the skin of larger fish, they don't only receive food from the relationship, eliminating parasite and such from the large fish, but also they gain protection from predators, thus making the relationship a good example of mutualism, because both parts of the relationship gain something from the relationship itself. </span>
The correct option is D.
If water density at freezing point is greater, the ice formed will sink to the bottom of the water body and freeze the water up from the bottom. This will surely lead to the death of everything that live inside the water.