How are HR Skills assigned to an agent?
HR skills are stored on the user record's Skills related list, so assignment happens through the agent's User Profile rather than the HR Profile or group membership. This directly satisfies the stem's question of how skills reach an agent.
Why this answer
HR Skills are assigned to agents through the User Profile/Skills management interface, where an HR agent's user record is updated with the relevant skills (e.g., Benefits, Payroll, Employee Relations). These skills are then used by HR Assignment Rules and routing logic to match cases to qualified agents. The skill assignment is a property of the agent's user profile, not of the HR service or catalog item.
Exam trap
CIS-HR often tests the confusion between where skills are stored (user profile) versus where they are consumed (assignment rules), causing candidates to pick Assignment Rule as the assignment mechanism.
How to eliminate wrong answers
Option A is wrong because Catalog Items are the requestable offerings employees submit, not the mechanism for tagging agents with skills. Option B is wrong because Assignment Rules consume skills to route work but do not assign the skills themselves to agents. Option C is wrong because an HR Service defines the case type and its associated workflows, not the agent's skill set.