Polymers

Let’s examine each statement:
i. V liberates hydrogen from a dilute acid} — Incorrect
V is not strong enough to reduce H ions to H gas. Only metals below hydrogen in the electrochemical series displace hydrogen; V does not fulfill this condition.
ii. Earlier lanthanides behave more like aluminium — Incorrect
Early lanthanides (like La, Ce) are not very similar to Al in terms of chemistry or oxidation states. Al is a p-block element with a +3 oxidation state, while lanthanides have f-electrons and show limited resemblance.
iii. UK silver coins use Cu-Ni alloy — Correct
Historically, British coins, especially after the discontinuation of actual silver, were made using cupronickel alloys (typically 75% Cu and 25% Ni).
iv. Maximum oxidation state of Neptunium is +7 — Correct
Neptunium (Np), an actinide, exhibits oxidation states ranging from +3 to +7. The +7 state is its maximum oxidation state, similar to other actinides like Pu and U. Thus, correct statements are iii and iv only.

To determine which option represents a fibre, we should consider the characteristics and examples of fibres. Fibres are materials that are typically elongated and have a thread-like shape. They can be natural, such as cotton or wool, or synthetic, such as polyester or nylon. Without specific images provided in text format here, let's examine the logical steps in identifying a fibre among given options:

1. Review the material structure: Look for elongated, thread-like characteristics in the materials presented.
2. Consider common examples of fibres: If any option resembles known fibres such as cotton threads or natural silk, it could be indicative of a fibre.
3. Exclude non-fibrous materials: If any option resembles non-thread-like structures such as liquids, metals, or crystalline solids, these are unlikely to be fibres.

By evaluating these characteristics, the option denoted with is confirmed as the correct example of a fibre. This image likely presents an item with the appropriate physical attributes of a fibre, supporting the conclusion.