What is the only lawful reason to classify information?

Classifying information serves a specific purpose related to national security. The primary goal of classification is to ensure that sensitive information is adequately protected from unauthorized disclosure, which could jeopardize the safety and security of a nation. By classifying information, governmental and military entities can safeguard intelligence, military plans, diplomatic communications, and other critical data that, if exposed, might undermine the integrity of national interests or operations.

Each of the other options focuses on motives that, while valid in different contexts, do not align with the lawful justification for classifying information under established guidelines. Maintaining corporate secrets can involve non-classified means such as trade secrets, and personal employee protection might address privacy concerns that are typically outside the realm of classification as a national security concern. Limiting public knowledge of operations may relate to transparency issues, but it does not encompass the overarching objective of classification, which is specifically aimed at protecting national security concerns.