In this sentence improvement item, choose the correct preposition to replace the bracketed word "(on)" in the sentence "Once you emerge as an individual, it is important to realise that your freedom has an impact on others."

Introduction / Context:
This question focuses on the correct preposition used with the noun "impact" in modern English. The sentence explains that an individual's freedom influences other people, and the phrase "impact on others" is already a very common and natural combination. You need to decide whether the bracketed preposition "on" should be changed or left as it is.

Given Data / Assumptions:

• Base sentence: "Once you emerge as an individual, it is important to realise that your freedom has an impact on others."
• The bracketed word is "on".
• The idea is that personal freedom influences other people.
• Options offer alternative prepositions or no improvement.

Concept / Approach:
In standard English, the most common pattern is "have an impact on something or someone". Examples include "technology has an impact on society" and "pollution has an impact on health". The preposition "on" expresses the target that is affected. Prepositions such as "at", "for", or "in" do not collocate with "impact" in this sense. Therefore, the original expression "impact on others" is already correct and requires no change.

Step-by-Step Solution:
Step 1: Identify the noun and preposition pair: "impact on". Step 2: Recall typical collocations from reading and listening: "impact on the environment", "impact on the economy". Step 3: Compare with alternatives such as "impact at", "impact for", or "impact in" and notice that they are not standard. Step 4: Conclude that the original combination "impact on others" is correct. Step 5: Choose "No improvement" as the best option.

Verification / Alternative check:
Try substituting each option in the sentence. "Impact at others" sounds completely wrong; "impact for others" changes the sense to doing something for their benefit; "impact in others" is not used in this context. Only "impact on others" matches the normal pattern in dictionaries and formal writing. If you consult articles on ethics and personal freedom, you will repeatedly see phrases like "the impact on society" rather than any other prepositional pattern.

Why Other Options Are Wrong:
"At" usually suggests direction towards a point, as in "look at" or "throw at", which does not fit with "impact" as a noun.

"For" indicates purpose or benefit, for example "a gift for you", but the sentence is about influence, not benefit or purpose.

"In" is used for location inside something, such as "in a box" or "in trouble", and does not match the fixed expression "impact on".

Common Pitfalls:
A frequent source of error is overthinking and changing phrases that are already correct in an attempt to make them sound more complex. In sentence improvement questions, always check whether the original phrase matches common usage. If it does, "No improvement" is often the safest and most accurate choice. Learning fixed pairs like "effect on", "influence on", and "impact on" will help you answer many similar questions quickly.

Final Answer:
The original phrase "impact on others" is correct, so the best answer is "No improvement".