In this English vocabulary question, select the single word that best substitutes the phrase "courteousness and refinement of manner".

Introduction / Context:
This question checks your knowledge of one word substitutes connected with behaviour and manners. The phrase "courteousness and refinement of manner" refers to polished, polite, and cultured social behaviour, especially in conversation and interaction. You must choose the word that exactly captures this meaning in formal English usage.

Given Data / Assumptions:

• The phrase to be replaced is "courteousness and refinement of manner".
• The options are "Urbanity", "Plaudit", "Adulation", "Profanity", and "Boastfulness".
• Only one of these words refers to polished manners and cultured behaviour.

Concept / Approach:
"Urbanity" is an English noun that denotes polished, refined, and courteous behaviour, especially associated with people from cities or cultivated backgrounds. The other options have very different meanings. "Plaudit" is a form of praise, "adulation" refers to excessive admiration, "profanity" means offensive or vulgar language, and "boastfulness" is about bragging. Matching the core idea of refined manners with the precise word leads you to the correct answer.

Step-by-Step Solution:
Step 1: Identify the central idea of the phrase: politeness plus refinement in social behaviour. Step 2: Recall the meaning of "urbanity". It refers to courteous, refined, and elegant manners. Step 3: Evaluate "plaudit". It means an expression of praise or approval, not a manner of behaving. Step 4: Evaluate "adulation". This word refers to exaggerated or excessive praise, again unrelated to refinement of manner. Step 5: Evaluate "profanity". It means language that is rude, offensive, or irreligious and is the opposite of refined behaviour. Step 6: Evaluate "boastfulness". This is the habit of talking proudly about oneself and is considered bad manners, not refinement. Step 7: Only "urbanity" fits both courteousness and refinement of manner.

Verification / Alternative check:
You can verify by recalling collocations like "his urbanity impressed everyone at the party" or "she spoke with wit and urbanity". In both cases, the word implies grace, politeness, and polished social behaviour. None of the other options naturally collocate with manners or refinement. This reinforces that "urbanity" is the correct one word substitute for the phrase in the question.

Why Other Options Are Wrong:
"Plaudit" and "adulation" focus on praising someone; they do not describe how a person behaves. "Profanity" is clearly negative, linked to bad language, and is the direct opposite of refinement. "Boastfulness" describes arrogant self praise and would be considered rude rather than courteous. Therefore, all these options fail to convey the idea of refined manners that the question demands.

Common Pitfalls:
Students sometimes pick a word simply because it has a positive tone, without matching it precisely to the phrase. Others may not have seen the word "urbanity" often and may feel uncertain about it. A good strategy is to learn vocabulary in word families with examples and context. For instance, connect "urban" with city, "urbane" with sophisticated, and "urbanity" with refined behaviour. This mental chain helps you remember meanings accurately.

Final Answer:
The correct one word substitute is Urbanity.