Select the most appropriate one-word substitution for the given group of words. 

An ability to make good judgements and take quick decisions.

Acumen

The most appropriate one-word substitution for the given group of words "An ability to make good judgments and take quick decisions" is "Decisive."

Explanation of the options:

☀ Decisive: Decisive refers to the ability to make decisions quickly and effectively, showing good judgment and resolve.

☀ Acumen: Acumen refers to keen insight, perception, or understanding, often related to a specific field or area of expertise. While acumen can contribute to making good judgments, it does not explicitly imply the ability to take quick decisions.

☀ Confident: Confident means having self-assurance and belief in one's abilities. While confidence can be a valuable trait in decision-making, it does not specifically denote the ability to make good judgments and take quick decisions.

☀ Confederation: Confederation refers to a group of individuals or states that have formed an alliance or union. It does not relate to the ability to make good judgments and take quick decisions.