The answer is D. The natural selection is a theory which illustrates the gradual process of evolution in the population due to the change of environment. The key point is the mutation (variation) exists in the population before the environment changing. For C, if the environment does not change, though the adaptation is useful to environment, it will not be selected. Because the organisms without the adaptation will not die.
When there is either a partial or complete tearing on ligaments that are responsible for supporting the joint of the ankle then it causes an ankle sprain.
Based on the exam findings as well as the loss in functionality of the ankle, an ankle sprain can be categorized as grade I, II or III.
In the given situation the 14-year-old girl has a grade II ankle sprain which is characterized by an incomplete tear of the ligaments along with moderate pain (as she rates it 5/10), moderate tenderness, loss of range of some functions, and swelling.
All of the characteristics of the sprain resemble those of the grade II ankle sprain tear and hence, it is characterized as a grade II ankle sprain.
