In this error spotting question, find the part of the sentence that contains an error: "He watched as fights (1) broke out (2) along the city. (3) No Error (4)".

Introduction / Context:
This is another error spotting question focused on the use of prepositions with place expressions. The sentence describes fights breaking out in a city, and the error is in the phrase "along the city". Understanding which prepositions naturally collocate with words like "city" is important for accurate English usage, especially in descriptive writing and reporting.

Given Data / Assumptions:

• The sentence is divided as "He watched as fights (1) broke out (2) along the city. (3) No Error (4)".
• The subject "He" and the verb phrase "watched as fights broke out" are grammatically correct.
• The problematic phrase is "along the city".
• The intended meaning is that fights happened in many parts or areas of the city.

Concept / Approach:
The preposition "along" is normally used with linear objects like roads, rivers, or walls, as in "along the river" or "along the road". When we talk about events happening within the limits of a town or city, we typically use "in the city", "throughout the city", or "across the city". Therefore "along the city" is not a natural or correct combination in standard English. The correct correction would be "across the city" or "throughout the city". Thus, the error is located in part (3).

Step-by-Step Solution:
Step 1: Read the entire sentence: "He watched as fights broke out along the city."Step 2: Confirm that "He watched" and "fights broke out" are correctly formed verb phrases.Step 3: Examine "along the city" and test alternative prepositions in your mind such as "in the city", "across the city", or "throughout the city".Step 4: Recognise that "along" does not match the noun "city" in this context because a city is not a simple line or edge.Step 5: Conclude that part (3) is the incorrect segment due to wrong preposition choice.

Verification / Alternative check:
Correcting the sentence to "He watched as fights broke out across the city" or "He watched as fights broke out throughout the city" gives a much more natural and idiomatic expression. No changes are needed in parts (1) and (2), and thus "No Error" in part (4) cannot be selected. This confirms that the mistake is confined to part (3) only.

Why Other Options Are Wrong:

• Option A (part 1 "He watched as fights") is grammatical and meaningful.
• Option B (part 2 "broke out") correctly describes the sudden start of fights and is a standard phrasal verb.
• Option D (part 4 "No Error") is wrong because we have clearly identified an error in the phrase "along the city".

Common Pitfalls:
Many learners treat prepositions as interchangeable, but exam questions often test knowledge of fixed combinations. "Along" works with long narrow locations, whereas "across" or "throughout" typically pair with wider areas like fields or cities. Training yourself to notice these patterns in reading materials will make such error spotting questions easier to answer accurately.

Final Answer:
The error is in part 3, where "along the city" should be replaced by a more suitable prepositional phrase such as "across the city" or "throughout the city".