Explanation:

- Option 1: Conclusive

- Conclusive evidence leaves no room for doubt. In auditing, evidence usually doesn't reach this level due to inherent limitations.

- Option 2: Concrete

- Concrete evidence is specific and tangible. While auditors seek strong evidence, not all audit evidence can be concrete.

- Option 3: Complete

- Complete evidence suggests that all necessary information has been gathered. This isn't often feasible in auditing due to constraints like time or resources.

- Option 4: Persuasive

- Auditors collect persuasive evidence, which is enough to support their conclusions. This aligns with the realistic goal of providing reasonable assurance rather than absolute certainty.

Correct Answer: Option 4 - Persuasive