English Vocabulary — Antonym (choose the word opposite in meaning to the highlighted word). Sentence: Feasibility of the project is under study.

Introduction / Context:
The problem assesses precision with near-synonyms and antonyms in project-management vocabulary. The noun “feasibility” corresponds to “practicability.” You are to select the nearest opposite from the given nouns.

Given Data / Assumptions:

• Target noun: feasibility = practicability, doability.
• Options include nouns with different semantic fields: cost, ethics, suitability, and feasibility-opposites.

Concept / Approach:
Antonym choice must negate the ability to execute in practice. “Impracticability” directly negates “practicability/feasibility,” while other options shift domains (ethics or cost) and therefore miss the lexical target.

Step-by-Step Solution:

Verification / Alternative check:
Paraphrase: “The impracticability of the project is under study.” This inverts the meaning while remaining in the correct technical domain.

Why Other Options Are Wrong:

• unsuitability: About fit or appropriateness, not executional possibility.
• cheapness: Cost-related; orthogonal to feasibility.
• impropriety: Ethical impropriety; wrong semantic field.

Common Pitfalls:
Confusing feasibility with suitability or affordability. Feasibility focuses on practical ability to implement, not whether it is proper or inexpensive.

Final Answer:
impracticability