Data definition standards within a database primarily support data formatting by establishing how data elements must be structured, represented, and stored. In practical terms, these standards define characteristics such as data type, field length, allowable values, precision, naming conventions, and valid formats. ISACA glossary material includes format checking as a control concept, which directly relates to verifying that data conforms to a prescribed format. That is the closest and strongest match to what data definition standards support.

Option C is correct because data definition standards are about consistency of data structure and representation. When an organization enforces common definitions for fields and attributes, it improves the consistency and usability of data across systems and applications. ISACA governance and data management material emphasizes that defining the format in which data are presented is part of giving data meaning and ensuring quality and usability.

Option A is incorrect because data disposal concerns end-of-life handling of data, such as destruction, archival expiration, and secure deletion. Those activities are governed by retention, records management, privacy, and disposal requirements, not by database data definition standards. ISACA privacy and data lifecycle guidance treats disposal as a separate lifecycle issue.

Option B is incorrect because data retention relates to how long data should be kept for business, legal, regulatory, or operational purposes. Retention policies may rely on data classification and legal obligations, but they are not what data definition standards primarily address.

Option D is incorrect because data confidentiality is mainly supported by access controls, encryption, classification, segregation of duties, and related security controls. Although well-defined data may indirectly help governance, confidentiality is not the main purpose of data definition standards.

Therefore, the best answer is C because enforcing data definition standards within a database most directly supports correct and consistent data formatting.

References (Official ISACA):

ISACA Glossary — Format checking.

ISACA, Unearthing and Enhancing Intelligence and Wisdom Within the COBIT 5 Governance of Information Model — discusses defining the format in which data are presented.

ISACA Journal, IS Audit Basics: Data Management Body of Knowledge—A Summary for Auditors — supports the role of data management standards and quality.

ISACA, SOC Reports for Cloud Security and Privacy — distinguishes use, retention, and disposal from data structure concerns.