The best option for ensuring confidentiality through the use of asymmetric encryption is to encrypt a message with the recipient's public key (option A). This is because:
* Asymmetric encryption, also known as public-key cryptography, is a type of encryption that uses a pair of keys to encrypt and decrypt data. The pair of keys includes a public key, which can be shared with anyone, and a private key, which is kept secret by the owner12.
* In asymmetric encryption, the sender uses the recipient's public key to encrypt the data. The recipient then uses their private key to decrypt the data. This approach allows for secure communication between two parties without the need for both parties to have the same secret key12.
* Encrypting a message with the recipient's public key ensures that only the recipient can decrypt it with their private key. This provides confidentiality, which means that the message is protected from unauthorized access or disclosure12.
* Encrypting a message with the sender's private key (option B) does not ensure confidentiality, but rather authentication, which means that the message can be verified as coming from the sender. This is because anyone can decrypt the message with the sender's public key, but only the sender can encrypt it with their private key12.
* Encrypting a message with the sender's public key (option C) or the recipient's private key (option D) does not make sense, as it would render the message unreadable by both parties. This is because neither party has the corresponding key to decrypt it12.
Therefore, the best option for ensuring confidentiality through the use of asymmetric encryption is to encrypt a message with the recipient's public key (option A), as this ensures that only the recipient can decrypt it with their private key.
References: 1: What is asymmetric encryption? | Asymmetric vs. symmetric ... - Cloudflare 2: What is Asymmetric Encryption? - GeeksforGeeks

While all the options can help reduce the risk of data leakage, providing education and guidelines to employees on the use of social networking sites would be the most effective. This is because it directly addresses the issue at hand - the use of social networking sites for business purposes1. Education and guidelines can help employees understand the risks associated with social media use and teach them how to safely and responsibly use these platforms for business purposes1. This includes understanding privacy settings, recognizing phishing attempts, and knowing what information should not be shared on these platforms1.
References:
10 Social Media Guidelines for Employees in 2023 - Hootsuite

The best approach for an IS auditor to evaluate whether the IT strategy supports the organization's vision and mission is to meet with senior management to understand the business goals and how IT can enable them.
This will help the IS auditor to assess the alignment and integration of IT with the business strategy and to identify any gaps or opportunities for improvement. Reviewing ROIs, KPIs, or feedback from other departments may provide some insights, but they are not sufficient to evaluate the IT strategy. References: IS Audit and Assurance Standards, section "Standard 1201: Engagement Planning"