In this aptitude classification question on textile materials, select the odd word from the given alternatives based on whether the fibre is natural or synthetic.

Introduction / Context:
This verbal reasoning question tests your ability to classify everyday materials based on a common scientific property. The options are names of fibres or fabrics, and you must select the one that does not belong with the others. Such odd one out questions are common in aptitude exams because they quickly check basic general knowledge and logical grouping skills.

Given Data / Assumptions:
- The given words are Nylon, Wool, Silk, and Cotton.- All of them are widely used in clothing and textiles.- We assume a basic science classification of fibres into natural and synthetic types.

Concept / Approach:
The most natural way to classify these items is by origin. Textile fibres are broadly divided into natural fibres and synthetic or man made fibres. Natural fibres come from plants and animals. Synthetic fibres are produced chemically in factories. If three of the given options are natural and one is synthetic, then the synthetic one will be the odd word out. We will therefore identify which fibre is man made.

Step-by-Step Solution:
Step 1: Wool is a natural animal fibre obtained mainly from sheep.Step 2: Silk is another natural animal fibre produced by silkworms.Step 3: Cotton is a natural plant fibre obtained from cotton plants.Step 4: Nylon is a fully synthetic fibre created through chemical processes in factories.Step 5: Thus, three fibres are natural, and only one fibre is synthetic.

Verification / Alternative check:
You can also group the fibres as plant based or animal based plus man made. Cotton is plant based, wool and silk are animal based, and nylon clearly stands out as artificial. This confirms that nylon does not share the natural origin property.

Why Other Options Are Wrong:
Wool: Natural animal fibre, so it belongs with silk and cotton.Silk: Natural animal fibre, similar in category to wool.Cotton: Natural plant fibre widely used in textiles.

Common Pitfalls:
Some learners focus on how commonly each fabric is used or whether it is warm or cool to wear. The question, however, is about which word does not fit logically into the same category of fibre origin. Always think in terms of classification rule, not personal preference.

Final Answer:
The odd word is Nylon because it is a synthetic fibre while the others are natural fibres.