Which of these best represents an ecosystem?
A A herd of deer grazing in a field
® Mushrooms decomposing organic matter
© A pitcher plant growing in nutrient-poor soil
• Frogs and fish swimming in a pond in the forest
The correct answer is: ® Mushrooms decomposing organic matter
An ecosystem consists of a community of living organisms (such as mushrooms) interacting with each other and their physical environment (such as decomposing organic matter) within a specific area. This example represents the relationship between decomposers (mushrooms) and the process of decomposition in an ecosystem. The other options represent different elements or organisms within an ecosystem, but do not fully encompass the concept of an ecosystem as a whole.