Maximum Tolerable Outage (MTO) (A) defines the longest time an organization can tolerate an IT service being unavailable before significant business impact occurs. It determines business continuity planning and disaster recovery strategies.
Other options:
RPO (B) defines acceptable data loss but does not determine the total outage limit.
SDO (C) is related to service agreements but does not set the risk threshold.
AIW (D) is similar to MTO but is not as commonly used in disaster recovery planning.
Reference: ISACA CISA Review Manual, Information Systems Operations and Business Resilience

A network firewall is a device or software that monitors and controls the incoming and outgoing network traffic based on predefined rules. A network firewall can help reduce the risk of denial of service (DoS) attacks, which are attempts to overwhelm a system or network with excessive requests or traffic, by filtering or blocking unwanted or malicious packets. A SQL injection attack is a type of code injection attack that exploits a vulnerability in a web application's database query, by inserting malicious SQL statements into the input fields. A phishing attack is a type of social engineering attack that attempts to trick users into revealing sensitive information or installing malware, by sending fraudulent emails or messages that impersonate legitimate entities. An insider attack is a type of malicious activity that originates from within an organization, such as employees, contractors, or partners, who abuse their access privileges or credentials to compromise the confidentiality, integrity, or availability of information systems or data. A network firewall cannot prevent these types of attacks, as they rely on exploiting human or application weaknesses rather than network vulnerabilities.

A database conflict occurs when the same data is modified at two separate servers, such as a customer database and a remote call center database, and the changes are not consistent with each other. For example, if a customer updates their phone number at the customer database, and a call center agent updates the same customer's address at the remote call center database, there is a conflict between the two updates. Database conflicts can cause data inconsistency, corruption, or loss if they are not detected and resolved properly.
Two-way replication is a process of synchronizing data between two databases, so that any changes made in one database are reflected in the other database, and vice versa. Two-way replication can improve data availability, performance, and scalability, but it also increases the risk of database conflicts. Therefore, when assessing a proposed project for the two-way replication of a customer database with a remote call center, the IS auditor should ensure that database conflicts are managed during replication. This means that the project should have a clear and effective strategy for:
* Preventing or minimizing database conflicts by using techniques such as locking, timestamping, or partitioning.
* Detecting or identifying database conflicts by using tools such as triggers, logs, or alerts.
* Resolving or handling database conflicts by using methods such as priority-based, rule-based, or user- based resolution.
The other possible options are:
* B. end users are trained in the replication process: This is not a relevant or important factor for the IS auditor to ensure when assessing a proposed project for the two-way replication of a customer database with a remote call center. End users are not directly involved in the replication process, and they do not need to have detailed knowledge or skills about how replication works. The replication process should be transparent and seamless to the end users, and they should only interact with the data through their applications or interfaces.
* C. the source database is backed up on both sites: This is not a sufficient or necessary factor for the IS auditor to ensure when assessing a proposed project for the two-way replication of a customer database with a remote call center. Backing up the source database on both sites can provide some level of data protection and recovery, but it does not address the issue of database conflicts that can occur during replication. Moreover, backing up the source database on both sites may not be feasible or efficient, as it may consume more storage space and network bandwidth, and introduce more complexity and overhead to the replication process.
* D. user rights are identical on both databases: This is not a critical or relevant factor for the IS auditor to ensure when assessing a proposed project for the two-way replication of a customer database with a remote call center. User rights are the permissions or privileges that users have to access or modify data in a database. User rights do not directly affect the occurrence or resolution of database conflicts during replication. User rights may vary depending on the role or function of the users in different databases, and they should be defined and enforced according to the security policies and requirements of each database.

The best way to validate that appropriate security controls are in place to prevent data loss is to review compliance with data loss and applicable mobile device user acceptance policies. This will ensure that the organization has established clear rules and guidelines for employees to follow when connecting their personal devices to company-owned computers. A walk-through, a DLP tool configuration, and a security awareness training are not sufficient to validate the effectiveness of the controls, as they may not cover all possible scenarios and risks. References: IT Audit Fundamentals Certificate Resources