While at first glance it may seem that A might be a plausible option, the section emphasizes the human struggle to keep a flame alive and the old process for how fire was procured. Rather than perhaps nature and it’s starting of the first fires (if this was the case then the section would continue this theme further on, yet this doesn’t happen). Furthermore both answers B and D are also quite unlikely as they do not relate as much to the content at hand.
