In the following question, choose the option that best expresses the meaning of the idiom "To make a long story short".

Introduction / Context:
This question tests your understanding of a common English idiom: "To make a long story short". Idioms are fixed expressions whose overall meaning is not always obvious from the meanings of the individual words. Knowing such expressions is crucial for fluent reading, listening, and speaking, especially in narrative contexts where speakers summarise events.

Given Data / Assumptions:

• Idiom: "To make a long story short".
• Options describe different possible interpretations of this idiom.
• You must select the option that best captures its real usage in English.

Concept / Approach:
The idiom "to make a long story short" is typically used by a speaker when they decide to skip many details and jump directly to the main point or conclusion of a story. It signals that a summary is coming and that the listener will hear the essential outcome without all the intermediate events. Therefore, the correct answer must reflect the idea of summarising or ending a long account quickly.

Step-by-Step Solution:
Step 1: Recall the everyday usage of the idiom. For example, a speaker might say, "To make a long story short, we missed the train" after explaining that many events led to that outcome. Step 2: Examine option (A): "A very long boring narrative". This describes the opposite situation. The idiom is used to avoid a long narrative, not to describe one. Step 3: Examine option (B): "One should always communicate with fewer words wherever possible". This is a general piece of advice and does not match the specific conversational function of the idiom. Step 4: Examine option (C): "Used to end an account of events quickly". This correctly captures the idea that the speaker is cutting the story short and going directly to the main point. Step 5: Examine option (D): "When you want the complete details and not just the summary". This expresses the opposite of what the idiom signals. Step 6: Conclude that option (C) best expresses the meaning of the idiom.

Verification / Alternative check:
Insert option (C) into a natural sentence to verify: "I could tell you everything that happened, but to make a long story short, I lost my passport." This clearly means the speaker is cutting the explanation short. No other option fits so naturally into standard conversational patterns, confirming option (C) as correct.

Why Other Options Are Wrong:
Option (A) misunderstands the idiom and describes what is being avoided, not what is being done. Option (B) generalises about communication style and does not correspond to the specific phrase speakers use when summarising. Option (D) reverses the meaning. When someone wants complete details, they would not say "to make a long story short".

Common Pitfalls:
Some learners confuse the idiom with a comment on the quality of the story itself, assuming it refers to stories that are long and boring. In reality, it is about the speaker's decision to summarise. Also, learners may be misled by options that sound like reasonable advice about communication but do not match the idiom's function in real speech. Always think of example sentences in which you have seen the idiom used and match the option to that usage.

Final Answer:
"To make a long story short" is used to end an account of events quickly, giving only the essential points.