In the following question, out of the four alternatives, select the alternative which is the best substitute of the given group of words. Free from disturbance.

Introduction / Context:
This question tests knowledge of one word substitutes. The phrase free from disturbance needs to be replaced by a single word that captures the same meaning. Such questions are common in English sections of competitive exams because they assess vocabulary depth and the ability to compress an idea into a precise word. Recognising the correct term helps in both reading comprehension and writing with clarity and style.

Given Data / Assumptions:

• The phrase to be replaced is free from disturbance.
• The options given are Tranquil, Agitated, Chaotic, Violent, and Restless.
• We must choose the word that expresses calmness and absence of disturbance.
• We assume standard meanings for all options, as found in general English dictionaries.
• The positive, peaceful sense of the phrase should guide our selection.

Concept / Approach:
To be free from disturbance is to be calm, peaceful, and undisturbed. The word tranquil directly expresses this state. It can describe a place, such as a tranquil village, or a mental state, such as a tranquil mind. In contrast, words like agitated, chaotic, violent, and restless signal strong movement, disorder, or emotional turmoil. Thus, the basic approach is to group the options by whether they suggest peace or unrest and then choose the peaceful one.

Step-by-Step Solution:
Step 1: Restate the phrase free from disturbance as calm and peaceful, with no noise or trouble. Step 2: Examine Tranquil. This word means calm, quiet, and peaceful, which is a direct match. Step 3: Consider Agitated, which describes someone who is disturbed, upset, or nervous, the opposite of tranquil. Step 4: Chaotic refers to complete disorder and confusion, which is again far from being free from disturbance. Step 5: Violent indicates forceful and often harmful physical action, suggesting great disturbance. Step 6: Restless means unable to relax or be still, showing inner disturbance rather than peace. Step 7: Conclude that Tranquil is the only option that matches the given definition.

Verification / Alternative check:
Use example sentences. A tranquil lake and a lake free from disturbance both paint a picture of still water with no waves or noise. An agitated lake, chaotic lake, or violent lake would suggest storms or strong currents, which contradicts the idea. Similarly, a tranquil mind is free from disturbance, while an agitated or restless mind is disturbed. These examples confirm that tranquil is the best one word substitute.

Why Other Options Are Wrong:
Agitated is incorrect because it indicates emotional or physical disturbance, the exact opposite of calm. Chaotic suggests a situation full of confusion, which is a strong form of disturbance. Violent is associated with aggression and physical force, which disturbs peace. Restless refers to someone or something that cannot stay calm or still, again implying disturbance. None of these can substitute for free from disturbance without completely reversing the meaning.

Common Pitfalls:
A pitfall in such questions is to mistake familiar words with positive connotations for correct choices. However, even positive words can have meanings unrelated to the given phrase. It is important to focus on the core idea. In this case, the absence of disturbance suggests calmness and stillness. Developing the habit of thinking in simple synonyms first, such as calm for free from disturbance, and then mapping to the more advanced word tranquil can help resolve such items quickly.

Final Answer:
The correct one word substitute is Tranquil.