The RMF Step and task where the Information System is registered with the appropriate organization and PMO. Response:

RMF Step 1 is "Prepare," and Task 3 within this step is "Register System." This task involves formally registering the information system with the appropriate organizational entities, such as the Chief Information Officer (CIO) and the Program Management Office (PMO), to ensure it is recognized within the organization's enterprise architecture and risk management portfolio.

RMF Step 1, Task 1 is "Identify Organization-Level FIPS 199 Impact."

RMF Step 1, Task 2 is "Define System-Level Boundary."

RMF Step 1, Task 4 is "Identify Stakeholders and Roles."