In the following question, out of the four alternatives, select the one word which can be used as the best substitute for the given group of words. “Take away or alter the natural qualities of.”

Introduction / Context:
This question tests one word substitution, a common topic in English vocabulary sections of competitive exams. The phrase given is “Take away or alter the natural qualities of.” The learner has to find a single word that most accurately expresses this idea. Such questions help improve precision in language and understanding of nuanced scientific or technical vocabulary.

Given Data / Assumptions:
- Phrase: “Take away or alter the natural qualities of.”- Option A: “Denature”- Option B: “Unadulterated”- Option C: “Authentic”- Option D: “Limpid”- The task is to choose the most precise one word substitute.

Concept / Approach:
We first identify the key idea: changing or removing the natural qualities of something. In science, especially chemistry and biology, the verb “denature” is used when the natural structure of a protein or other substance is altered so that it no longer has its original properties. In a broader sense, “denature” can mean to modify something so that its original or natural characteristics are lost. The other options describe purity, genuineness, or clarity rather than the act of altering natural qualities.

Step-by-Step Solution:
Consider Option A, “Denature.” In scientific usage, it means to modify the molecular structure of a substance so that its original properties are changed or destroyed, as in “heat can denature proteins.” In general usage, it can mean altering the natural character of something. This matches the phrase “take away or alter the natural qualities of.”Option B, “Unadulterated,” means pure, not mixed with any other substance, free from contamination. This is almost the opposite of having natural qualities taken away.Option C, “Authentic,” means genuine or real, exactly as claimed. This emphasises original or true character, not the act of changing it.Option D, “Limpid,” means clear or transparent, often used for liquids or styles of writing. It says nothing about changing or removing natural qualities.Thus, only “Denature” captures the meaning “take away or alter the natural qualities of.”

Verification / Alternative check:
Test the phrase in a sentence: “Certain chemicals can denature milk and change its texture.” Here, the natural qualities of milk are altered. If we use the other options, the meaning collapses. “Unadulterated” would mean the milk remains pure; “authentic” would mean it is genuine milk; “limpid” would describe clarity. None of these express the act of changing or removing natural qualities.

Why Other Options Are Wrong:
“Unadulterated” is wrong because it focuses on purity rather than loss or change of natural qualities.“Authentic” is wrong because it indicates genuine or original state, not modification.“Limpid” is wrong because it simply refers to clarity and does not relate to altering qualities.

Common Pitfalls:
Some learners may be misled by the idea that long or sophisticated words like “unadulterated” fit every complex description. However, the key is to look carefully at the definition given in the question. The phrase clearly describes an action that changes natural qualities, which is exactly what “denature” means. Remember that in one word substitution questions, precision is more important than general positive or negative connotations.

Final Answer:
The best one word substitute for “Take away or alter the natural qualities of” is Denature.