Comprehensive and Detailed Explanation:

In the CMMC framework, asset types are categorized based on their role in handling or protecting CUI. The Network Admin manages the next-generation firewall (NGFW), which is a critical component in securing the data flow of CUI between the DoD’s Secure File-Sharing Application and the contractor’s internal systems. Per the CMMC Assessment Scope - Level 2, Security Protection Assets (SPAs) are defined as assets that provide security functions or capabilities to the contractor’s CMMC Assessment Scope, irrespective of whether they directly process, store, or transmit CUI. The Network Admin, by managing the NGFW, fulfills a security protection role, making them an SPA.

Option A (CRMA) applies to assets that can but are not intended to process, store, or transmit CUI due to risk management policies, which does not fit the Network Admin’s active security role. Option C (Specialized Asset) includes items like OT or government-furnished equipment, not personnel. Option D (CUI Asset) applies to assets that directly handle CUI, like the SSD or laptop, not the admin managing security. Thus, B is correct.