I believe your answer is B :)
Answer:
the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.
Explanation:
A gateway substance is something that may be menial but could lead to something bigger, an example is weed in the drugs world, weed is not hard to get and is usually a gateway drug to stronger types of drugs and potentially more dangerous
size hence streams are little and rivers are bigger than streams because a stream connects between two or more rivers
mark brainliest please :)