Answer:
The correct answer is option B. "An jar with snails crawling on living plants".
Step-by-step explanation:
A sealed container comprised of an jar with snails crawling on living plants, represents continuously cycle O2 and CO2 gases between the organisms. The plants produce O2 by consuming CO2 in the photosynthesis process, and the snails produce CO2 and consume O2 during the respiration process.