Machine shredding is the process of using a shredding machine to physically destroy the media and make the data unrecoverable. This is more effective than software formatting, which only erases the data logically and may leave traces that can be recovered by special tools1. Encrypting and destroying keys may prevent unauthorized access to the data, but it does not erase the data from the media. Wiping and rewriting three times is unnecessary and may reduce the lifespan of the media, especially for solid state drives2. Machine shredding is also recommended by various security standards and guidelines for media disposal345.

The finding that should be of greatest concern to an IS auditor assessing the effectiveness of an organization' s vulnerability scanning program is that results are not reported to individuals with authority to ensure resolution. This indicates a lack of accountability and communication for vulnerability management, which may result in unresolved or delayed remediation of identified vulnerabilities. This may expose the organization to increased risk of cyberattacks or breaches. The other findings are also concerning, but not as much as this one, because they may affect the completeness, accuracy or timeliness of the vulnerability scanning process, but not necessarily its effectiveness. References:
* ISACA, CISA Review Manual, 27th Edition, chapter 4, section 4.41
* ISACA, COBIT 2019 Framework: Introduction and Methodology, section 3.2

The primary benefit of using one-time passwords is that an intercepted password cannot be reused, as it is valid only for a single login session or transaction. One-time passwords enhance the security of authentication by preventing replay attacks or password guessing. The other options are not the primary benefits of using one-time passwords. Security for applications can be automated with or without one-time passwords. Users may still have to memorize complex passwords or use a device or software to generate one-time passwords. Users can still be locked out of an account if they enter an incorrect or expired one-time password.
References: CISA Review Manual (Digital Version), Chapter 6, Section 6.1