Explanation: The public or commercial data classification is also built upon a four-level model, which are as follows: Public Sensitive Private Confidential Each level (top to bottom) represents an increasing level of sensitivity. The public level is similar to unclassified level military classification system. This level of data should not cause any damage if disclosed. Sensitive is a higher level of classification than public level data. This level of data requires a greater level of protection to maintain confidentiality. The Private level of data is intended for company use only. Disclosure of this level of data can damage the company. The Confidential level of data is considered very sensitive and is intended for internal use only. Disclosure of this level of data can cause serious damage to the company. Answer: C and E are incorrect. Unclassified and secret are the levels of military data classification.