Which of the following combinations can be regarded as sub-systems within the ecosystem?

A. food chain, hydrological cycle, mineral nutrient cycle
B. hydrogical cycle, mineral nutrient cycle, evironmental controls
C. Mineral nutrient cycle, hygrological cycle, ecosystem controls
D. Ecosystem controls, food chain, hydrological cycle
E. Food chain, ecosystem controls, environmental controls

Correct Answer:

Option A – food chain, hydrological cycle, mineral nutrient cycle