The correct option is
A The process of adding earthworms to the waste material to help decomposition
Vermicomposting is a method by which compost or mixed manure of organic origin is prepared by the use of earthworms. It is a controlled degradation or decomposition of the organic wastes for the consumption of earthworms which helps in the recycling of food wastes, reduces the waste bulk density and the final product may contain hormone-like substance which accelerates the plant growth.
So, the correct answer is 'The process of adding microorganisms to the waste material to help decomposition'.