The correct option is C Assertion is a true statement but the reason is a false statement
The ecosystem is the structural and functional unit of nature where the living organisms interact with each other and with the surrounding environment.
Ecosystem consists of biotic (plants, animals, microbes) and abiotic (sunlight, soil, temperature) components.
There is interaction between the biotic and abiotic components of the ecosystem, which is required for the sustenance of the ecosystem.
Plants absorb mineral nutrients from the soil for their growth and metabolism. These are present in the soil due to the activity of decomposers like bacteria and fungi.
The decomposers obtain nourishment from the dead and decaying organic matter. They secrete the enzymes which degrade the complex organic matter and convert it into simple inorganic nutrients. They absorb a part of these nutrients for their metabolic activities and the remaining nutrients are added to the soil. These nutrients are absorbed by plants for their growth and development.
Hence, assertion is true but the reason is false.