Validation of rules by the business is the most helpful in establishing a baseline for measuring data quality because it ensures that the rules reflect the business needs and expectations. Validation of rules by the business also helps to identify and resolve any inconsistencies or conflicts among different data sources or stakeholders. Input from customers, industry standard business definitions and built-in data error prevention application controls are useful for improving data quality, but they are not sufficient for establishing a baseline. References: CISA Review Manual (Digital Version) 1, Chapter 5, Section 5.4.1

The type of control that is in place when an organization has established hiring policies and procedures designed specifically to ensure network administrators are well qualified is directive. Directive controls are those that guide or direct the actions of individuals or groups to achieve a desired outcome. Directive controls can also help to prevent or reduce the occurrence of undesirable events. Hiring policies and procedures are examples of directive controls that aim to ensure that only qualified and competent personnel are employed to perform IT-related tasks. References:
* CISA Review Manual (Digital Version), Chapter 4, Section 4.11
* CISA Online Review Course, Domain 1, Module 2, Lesson 12

Version control is a process of managing changes to an application or a document. It ensures that only the latest approved version of the application is used by end-users, which reduces the risk of errors, inconsistencies, and unauthorized modifications. Version control also allows tracking the history of changes and restoring previous versions if needed.