Which of the following situations would fulfill the author’s prophecy for swimming?

This question refers you to the conclusion sentence. The author states clearly that swimming must either progress into a new form or regress to the primal mode of movement. Choice B and D can be eliminated because they show no change, just a continuation of current circumstances. Choice A is an actual possibility as humans may very well be settling in outer space in the future.Choice A is the most realistic and relevant prophecy according to the premises developed by the author.