What is a "system high" security policy?什么是一个“系统高”的安全策略？（）

• A、A system where all users are cleared to view the most highly classified data on the system.系统上的所有用户被许可查看最高级别的数据
• B、A system that contains only data of one security classification.只包含一个安全级别的数据
• C、A system with data that contains only data of the highest security classification.只包含最高安全级别的数据
• D、A system that uses a Multi-Level Security Policy to separate the highly classified data from the other data residing on the system.使用多级安全策略去划分高级别数据和其他数据。