Which of the following actions is permitted in the Decision Manager Portal?

In the Decision Manager Portal, the addition of new propositions is indeed a permitted action. Propositions represent offers that can be made to customers based on specific criteria or decisions, and they are crucial for implementing effective decision strategies. By allowing users to create new propositions, the portal supports the dynamic and targeted marketing strategy that decisioning applications require. This capability ensures that decision-making processes can adapt as business needs change or evolve, allowing for a more personalized approach to customer engagement.

In the context of the other options, adding new groups, strategies, or issues typically falls outside the scope of direct actions permitted within the Decision Manager Portal. While users can manage and manipulate existing strategies and data within the portal, the creation of new ones often requires different levels of access or functionality that are not inherent to the portal's direct purposes. Focusing on the management of propositions allows for precise marketing actions that impact customer interactions effectively.