Answer:
The correct answer is option D. "discovered chemolithotrophs in natural environments".
Step-by-step explanation:
Sergei Nikolaievich Winogradsky was a ecological and soil scientist famous for being a pioneer for the definition of the concept of cycle of life. Winogradsky is also known for being the first scientist who discovered chemolithotrophs in natural environments. He made this achievement during his research with Beggiatoa in 1887, reporting that this organism was able to oxidize hydrogen sulfide as an energy source.