Step 1: Understanding the Concept:
Retting is a post-harvest biochemical extraction process used to separate bast fibres from the woody core and non-fibrous bark tissues of plants.
Step 2: Detailed Explanation:
Jute (Corchorus spp.) stems are bundled and steeped in slow-moving or stagnant fresh water.
Aquatic anaerobic and aerobic microorganisms (primarily pectinolytic bacteria such as Clostridium and Bacillus species) secrete enzymes (pectinases and hemicellulases) that break down the cementing gums, pectins, and hemicelluloses binding the individual bast phloem fiber bundles together, leaving the clean cellulose fibers intact.
Step 3: Final Answer:
Thus, retting of jute is a Microbiological Process, matching option (C).