Answer:
A). Organisms within a population compete with each other to survive.
Step-by-step explanation:
Charles Darwin in his evolution theory proposed that the organisms of all species emerge and develop via the 'natural selection' of tiny, inherited discrepancies and these disparities enhance the individual's ability to contest and compete with each other in order to survive and reproduce to continue their existence. This led to the emergence of the phrase 'survival of the fittest' which suggests that in this competition of 'natural selection', only the fittest will survive. Thus, option A is the correct answer.