D. Erosion;
Erosion is the only choice not linked to a living organism.
Biological processes are vital to sustain the life of living organisms. The processes are made up of chemical reactions. Consumption by animals is biological as the animal (living thing) is using what it consumes to help carry out chemical reactions in its body. Nitrogen fixation by bacteria is a biological process in a biochemical cycle. The microorganisms in the soil are living and carry out the process. Elimination of waste by animals is also a biological process as excretion is important to maintain homeostasis. Erosion is the only option not specified by/for a living organism.