Final answer:
The incorrect internal control practice for safeguarding trust assets among the options presented is 'Only one set of keys should be used for department locks,' as this does not ensure financial integrity or management of trust assets like the other options do.
Step-by-step explanation:
In assessing the question, "Examiners should assess the effectiveness of the institution's internal control practices in protecting and controlling trust assets. Controls may include all except the following: a. Only on set of keys should be used for department locks. b. Signature controls should be established for the disbursement of trust funds. c. More than one employee should be present when assets are received. d. Trust assets are required to be separated from the assets owned by the institution.", it's clear that the answer options are related to the controls implemented by financial institutions to protect trust assets. After reviewing the best practices in bank supervision and safeguarding trust assets, the option that does not fit as a common control measure would be: 'a. Only one set of keys should be used for department locks.' This control does not directly protect trust assets nor ensures their proper management, unlike the other options which relate directly to financial controls and segregation of duties.
As trustees and bank examiners play important roles in ensuring the integrity of financial systems, they typically follow strictly defined procedures and regulations, such as those monitored by the Office of the Comptroller of the Currency.