When an ecosystem has a scarce nutrient, that is when there is a nutrient limitation.
So the answer is C. <span>Nitrogen is typically the limiting nutrient in freshwater environments.
This is because Nitrogen is the "scarce" nutrient </span>
Answer: B - mosses and lichens that can grow on Rocky surfaces
Explanation: Primary succession usually starts or begins on rock outcrops. It could include bare surfaces, volcanic mountains or an area (water surfaces) with no soil.
In primary succession, pioneer organisms including algae, lichen, mosses and fungi usually are the pioneer species. Other abiotic factors like wind and water play roles of normalizing the habitat.
A hemopheliac is someone with a bleeding disorder resulting from any missing clotting factors in their blood. Vasoconstriction isn't generally the problem in hemophiliacs, nor is it the destruction of pathogens. If fibrin threads are not present to help form the platelet plug, then excessive bleeding occurs. Fibrin is one clotting factor that a hemophiliac may be missing which is then causing the disorder.