Concept:Cotton fibres are trichomes (hair-like outgrowths) that develop from the outer layer of the cotton seed, not from any part of the fruit wall or calyx.
Explanation:The cotton fibre is a soft, staple fibre that grows on the seed surface inside a protective boll.
It originates from epidermal cells of the seed coat.
Thus, it is a seed-coat fibre, not a fruit wall fibre.
Fibres are not obtained from the inner fruit wall, the fruit wall itself, or the calyx.
The cotton plant belongs to genus Gossypium, and the fibres help in seed dispersal.
Answer:C. Seed coat