Step 1: Understanding the Concept:
Textile fiber classification distinguishes regenerated cellulose fibers from regenerated natural protein fibers.
Step 2: Detailed Explanation:
Textile fiber generic classification (FTC standards):
1. Azlon: The generic standard term for all regenerated protein fibres manufactured from natural protein sources (such as milk casein [Lanital/Aralac], soybean protein [Soybean fibre], zein from maize [Vicara], or peanut protein [Ardill]).
2. Rayon, Lyocell, Cuprammonium Rayon: Regenerated cellulose fibres derived from dissolved wood pulp.
Step 3: Final Answer:
Hence, the regenerated protein fibre is Azlon, corresponding to option (C).