Final answer:
Performance evaluations prepared every three years indicate a weakness in the internal control environment, as infrequent evaluations may delay the detection of internal issues.
Step-by-step explanation:
Among the given options, performance evaluations being prepared every three years suggests a weakness in the internal control environment. Frequent performance evaluations are crucial for ensuring that employees remain aligned with the company's goals and regulatory requirements. By only conducting evaluations every three years, the company may not detect internal issues or areas that require improvement in a timely manner, potentially leading to significant oversight failures, similar to what occurred in the case of Lehman Brothers.