Choose the correct meaning of the idiom "to go the extra mile".

Introduction / Context:
Idioms are fixed expressions whose meanings cannot be understood simply by looking at the individual words. The phrase "to go the extra mile" is widely used in everyday English, especially in workplace and customer service contexts. It does not literally refer to walking an additional mile; instead, it has a figurative meaning.

Given Data / Assumptions:

• Idiom: "to go the extra mile."
• We must select the option that correctly explains its intended sense.
• Options include ideas about special effort, bonuses, getting lost, vehicles, and delaying journeys.

Concept / Approach:
"To go the extra mile" means to put in more effort than is strictly necessary, expected, or required in order to achieve something or to help someone. It often implies doing something additional or exceptional to ensure success or satisfaction. The idiom is commonly applied to employees who give outstanding service, students who work extra hard, or anyone who makes special sacrifices to achieve a goal.

Step-by-Step Solution:

Step 1: Recall typical usage: "She really went the extra mile to help her customers," or "If you want to succeed, you must go the extra mile in your preparation." Step 2: Compare each option with this idea. Option A describes "to make a special effort to achieve something," which exactly matches the sense of the idiom. Step 3: Note that options about bonuses, getting lost, or cars do not relate to effort or going beyond expectations. Step 4: Conclude that Option A correctly captures the figurative meaning.

Verification / Alternative check:
Try replacing the idiom with Option A in a sample sentence. "Our teacher always goes the extra mile to explain difficult topics" becomes "Our teacher always makes a special effort to explain difficult topics." The sentence still makes perfect sense. Substituting any other option, such as "to get an unexpected bonus" or "a vehicle which is very fuel efficient," would break the meaning of the sentence and sound absurd.

Why Other Options Are Wrong:

Option B: "to get an unexpected bonus" describes a reward, not the act of putting in extra effort. Option C: "to lose one's way and walk aimlessly" is unrelated and focuses on being lost, not on working harder. Option D: "a vehicle which is very fuel efficient" refers to cars, not to human effort or behaviour. Option E: "to delay starting an important journey" implies procrastination, which is almost the opposite of taking extra initiative.

Common Pitfalls:
Sometimes learners try to interpret idioms literally, imagining an extra kilometre or mile of travel. This leads to choosing options connected with walking, vehicles, or journeys. However, idioms must be understood as whole units with conventional meanings. A good strategy is to memorise idioms in example sentences so that their figurative sense becomes familiar.

Final Answer:
The idiom "to go the extra mile" means to make a special effort to achieve something.