Bacterial and fungal enzymes degrade detritus into simple organic substances, this process is called:
Fragmentation
Leaching
Catabolism
Mineralisation
As we have already discussed in Functions of Ecosystem: Decomposition -
Catabolism -
Bacterial and fungal enzymes degrade detritus into simpler inorganic substances. This process is called as catabolism.
Hence, the correct option is (c).