Which term is used to describe operations that ensure sensitive information is protected?

The correct term that describes operations aimed at protecting sensitive information is Information Security. This encompasses a broad range of practices and technologies that are specifically designed to ensure the confidentiality, integrity, and availability of information. It includes measures to protect data from unauthorized access and corruption, thereby maintaining the privacy of sensitive information.

While Communications Security focuses specifically on protecting unclassified communication from interception, and Operations Security refers to the process of identifying and protecting critical information from adversaries, they are subsets of the broader Information Security framework. Physical Security pertains to the measures taken to protect physical assets, but does not directly address information protection in the way Information Security does. Thus, the encompassing nature of Information Security makes it the most appropriate term in this context.