Which best describes the concept of natural selection? A. an organism will always mutate to survive
B. The fittest organisms are selected for
C. Nature selects the organisms with the most Mutations
D. mutations make organisms more fit

D.

Explanation:

Natural selection is the way that organisms adapt through adaptations to better survive and pass on the special genes which enable the offspring to survive. Saying an organism will always mutate to survive is wrong, as natural selection implies that not all organisms survive. With natural selection, nothing is "selected", so B and C are not correct. However, mutations DO make organisms "more fit" to survive their environments, so D is the answer.

the median of the data is 4.5.