In this English error-spotting question, identify the part of the sentence which contains an error in the comparison: "Everybody knows(1) that Bhutan is the most peaceful(2) of all other countries of the world.(3) No Error(4)".

Introduction / Context:
This question checks your ability to spot grammatical errors in comparative structures. The sentence given is: "Everybody knows that Bhutan is the most peaceful of all other countries of the world." The sentence is split into four parts, and you are required to identify which part contains the error. Such questions are very common in competitive exams to test your knowledge of comparative adjectives and redundant words like "other" when using superlatives such as "most peaceful".

Given Data / Assumptions:

• The sentence has four parts: (1) Everybody knows, (2) that Bhutan is the most peaceful, (3) of all other countries of the world, (4) No Error.
• We must find which numbered segment contains an error.
• The key grammar area is the use of a superlative degree adjective "most peaceful" with the phrase "of all other countries".
• We assume the intended meaning is that Bhutan is more peaceful than any other country in the world.

Concept / Approach:
When we use a superlative degree like "the most peaceful", we compare one item with all the members of a group including it. Therefore, we typically say "the most peaceful of all countries in the world" or "the most peaceful country in the world". The word "other" is not used with a superlative when the subject is included in the group. "Other" is used with comparative degree, for example, "more peaceful than any other country". Thus, the phrase "of all other countries of the world" is incorrect and redundant. It should be "of all countries of the world" or rephrased in some other correct way.

Step-by-Step Solution:
Step 1: Examine part (1) "Everybody knows" – this is grammatically correct and natural. Step 2: Examine part (2) "that Bhutan is the most peaceful" – "the most peaceful" is the correct superlative form for this context. Step 3: Examine part (3) "of all other countries of the world" – here we notice the combined use of "all" and "other" with a superlative. Step 4: Recall the rule: with superlative degree adjectives ("the most peaceful") we normally use "of all" or "in the world", not "of all other". Step 5: Realize that "other" is appropriately used with comparative structure such as "more peaceful than any other country". Step 6: Conclude that part (3) contains the error and should be corrected to "of all countries of the world" or "in the world".

Verification / Alternative check:
We can rewrite the sentence in two clearly correct ways: "Everybody knows that Bhutan is the most peaceful country in the world." or "Everybody knows that Bhutan is more peaceful than any other country in the world." The first sentence uses superlative degree correctly without "other". The second sentence uses comparative degree and includes "any other country", which is the correct combination. Therefore, the original phrase "of all other countries of the world" is neither of these standard patterns and must be considered incorrect.

Why Other Options Are Wrong:
Part (1) "Everybody knows" is a common, grammatically correct phrase; there is no issue with subject-verb agreement here. Part (2) "that Bhutan is the most peaceful" correctly uses the superlative degree "most peaceful" with the definite article "the". Part (4) represents "No Error" and is not itself a sentence component; the error has already been found in part (3).

Common Pitfalls:
Students often overlook redundancies when dealing with comparative and superlative structures. A frequent mistake is mixing up the patterns "the most ... of all" and "more ... than any other". Remember that "other" is not required with superlative degree and, in fact, makes the expression incorrect or awkward. During exams, whenever you see "most" combined with "other", inspect the sentence carefully, as it is often a clue to an error in usage.

Final Answer:
The error is in part 3, so option "3" is the correct choice.