Comprehensive and Detailed Step-by-Step Explanation:
Failure torevoke access upon terminationposes the greatest security risk, as ex-employees could still access sensitive data or systems.
* No Policy to Revoke Access (Correct Answer - A)
* A terminated employee retaining access can lead todata breaches or insider threats.
* Example:A former employee misuses active credentials to access financial systems.
* Lack of Security Awareness Training (Incorrect - B)
* Important but does not pose an immediate security risk like an active ex-employee account.
* No NDAs (Incorrect - C)
* Protects intellectual property but is not as critical as system access.
* No Access Revocation for Role Changes (Incorrect - D)
* Still a concern, but ex-employees with active access are ahigherrisk.
References:
* ISACA CISA Review Manual
* NIST 800-53 (Access Control)

Before sending backup drives to an offsite storage facility, the most important thing to do is to encrypt the drive with strong protection standards. This is because encryption ensures effective security where information cannot be intercepted and used to harm the organization or its customers. Encryption also protects the data from unauthorized access, modification, or deletion in case the drive is lost, stolen, or damaged during transit or storage. Encryption of backup drives is especially important for public safety organizations that handle sensitive or personally identifiable information, such as medical records, criminal records, or emergency communications12.

Incremental backups are backups that only copy the data that has changed since the last backup, whether it was a full or incremental backup. The main reason to use incremental backups is to minimize the backup time and resources, as they require less storage space and network bandwidth than full backups. Incremental backups can also improve key availability metrics, such as recovery point objective (RPO) and recovery time objective (RTO), but that is not their primary purpose. Reducing costs associated with backups and increasing backup resiliency and redundancy are possible benefits of incremental backups, but they depend on other factors, such as the backup frequency, retention policy, and media type. References: CISA Review Manual (Digital Version): Chapter 5 - Information Systems Operations and Business Resilience

The best assurance of data integrity after file transfers is hash values. Hash values are unique strings that are generated by applying a mathematical function to the data. Hash values can be used to verify that the data has not been altered or corrupted during the transfer, as any change in the data would result in a different hash value. By comparing the hash values of the source and destination files, one can confirm that the data is identical and intact.
The other options are not as effective as hash values for ensuring data integrity after file transfers. Check digits are digits added to a number to detect errors in data entry or transmission, but they are not reliable for detecting intentional or complex modifications of the data. Monetary unit sampling is a statistical sampling technique used for auditing financial statements, but it is not applicable for verifying data integrity after file transfers. Reasonableness check is a validation method that checks whether the data falls within an expected range or format, but it does not guarantee that the data is accurate or consistent with the source.
References:
* 5: On Windows, how to check that data is unchanged after copying? - Super User
* 6: Data integrity | Cloud Storage Transfer Service Documentation | Google Cloud
* 7: Checking File Integrity - HECC Knowledge Base
* 8: How to setup File Transfer Integrity Checks - Progress.com