Of the following, which is NOT a risk assessment system?

The Aggregated Countermeasures Effectiveness (ACE) Model is a documented approach used in risk assessment to evaluate the combined effectiveness of security countermeasures.

The 'Information Security Protection Assessment Model (ISPAM)' is not a commonly known or established risk assessment framework or system within cybersecurity literature or practice. The other options refer to actual, albeit sometimes specialized or historical, risk assessment methodologies.

Dollar-based OPSEC Risk Analysis (DORA) is a recognized quantitative risk analysis method that calculates risk in monetary terms, often for operational security.

Analysis of Networked Systems Security Risks (ANSSR) is a documented framework for assessing security risks specifically within networked environments.