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. “Decay of organic matter producing a fetid smell.”

Introduction / Context:
This is another one word substitution question. The phrase given is “Decay of organic matter producing a fetid smell.” The learner must choose the single word that most accurately describes this process. Such vocabulary is particularly useful in scientific descriptions, environmental studies, and descriptive writing.

Given Data / Assumptions:
- Phrase: “Decay of organic matter producing a fetid smell.”- Option A: “Putrefy”- Option B: “Crisp”- Option C: “Neoteric”- Option D: “Virgin”- The task is to select the word that best captures the meaning of decay that produces a foul odour.

Concept / Approach:
We focus on the key ideas: decay, organic matter, and a foul or fetid smell. In English, “putrefy” means to decay or rot, especially with an offensive smell, as happens with dead animals or rotting food. The noun form “putrefaction” describes the process. The other options have meanings related to freshness, newness, or purity, which are clearly not describing decay.

Step-by-Step Solution:
Option A, “Putrefy,” is a verb meaning to undergo putrefaction, to decompose and produce a very unpleasant smell. This directly matches the description “decay of organic matter producing a fetid smell.”Option B, “Crisp,” usually describes something firm, dry, and brittle in a pleasant way, such as crisp apples or crisp toast. It can also describe cool and fresh air. It has no connection with decaying, smelly matter.Option C, “Neoteric,” means modern or new. It is used for recent ideas or styles and is the opposite of decayed or rotten.Option D, “Virgin,” generally means pure, untouched, or unused. It conveys freshness and absence of prior use, again the opposite of rotting matter.Therefore, the only word that correctly matches the given phrase is “Putrefy.”

Verification / Alternative check:
Test Option A in a sentence: “The discarded meat began to putrefy in the heat, filling the air with a fetid smell.” This directly shows decay of organic matter and offensive odour. None of the other options fit in such a context. For example, “The discarded meat became crisp,” “became neoteric,” or “became virgin” would be nonsensical.

Why Other Options Are Wrong:
“Crisp” is wrong because it refers to a pleasant firmness or freshness, not decay.“Neoteric” is wrong because it means new or modern, which is unrelated to rotting organic matter.“Virgin” is wrong because it indicates purity or untouched state, not decomposition.

Common Pitfalls:
Learners may sometimes be unfamiliar with “putrefy” and may try to guess based on sound or length of the word. It is helpful to connect “putrefy” with “putrid,” another word for something that smells very bad due to rot. Recognising this family of words makes it easier to recall the meaning precisely.

Final Answer:
The one word substitute for “Decay of organic matter producing a fetid smell” is Putrefy.