In plant seeds, the photoreceptor phytochrome is responsible for the process termed photomorphogenesis<span>. This occurs when a seed initially situated in an environment of complete darkness is exposed to light. A brief exposure to electromagnetic radiation, particularly that whose wavelength is within the red and far-red lights, results in the activation of the photorecepter phytochrome within the seed. This in turn sends a signal through the signal transduction pathway into the nucleus, and triggers hundreds of genes responsible for growth and development</span>
It might be stated that his reliability might be compromised because he writes the story many years later and his memories may be skewed. he is the narrator and the protagonist of the story and it is written in first person so he retells what he remembers from his life experience since he was a child.
The answer is the first one.
I think it 700 million years because I took the same question and that’s what I put.