Answer:
Option B, Nature
Step-by-step explanation:
All natural processes are governed by some scientific phenomena. Be it color of clouds, water & sky, occurrence of day/night or seasons, rainfall, earthquake or any other natural process, all have a scientific explanation for their causes or occurrence.
But subjects like astrology and spirituality are pseudoscience, which include concepts believed by people since ages without any scientific explanation of it.
Like wise philosophy is also a study of general observation about human behaviour, languages, society standards & existence which up to some extent can be explained by science but not completely.
Thus, option B is correct.