Explanation/Reference: https://graser.co.at/cobit-5-understand-the-framework-2/

The responsible role fulfills the practice and creates the intended outcome within an organizational structure chart (RACI chart). A RACI chart is a tool that assigns different levels of responsibility, accountability, consultation, and information to roles and organizational structures for each governance and management objective. The responsible role means performing or overseeing a task or process. There can be more than one responsible role for each task or process, but they must be coordinated by the accountable role. The responsible role fulfills the practice and creates the intended outcome by executing or supervising the process activities.13 References: COBIT 2019 Framework: Introduction and Methodology, COBIT 2019 Framework: Roles, Responsibilities & RACI Charts

Within the COBIT organizational structures component, the Accountable (A) role is solely liable for the success and achievement of assigned tasks. This role has the authority to approve or veto any decision or activity related to the tasks, and is responsible for ensuring that the Responsible role has adequate resources and skills to perform the tasks2, p. 34. References: 2: COBIT 2019 Framework: Introduction and Methodology

The primary role of business leadership when defining the future state in a business case is to determine the capabilities required from IT. This is accomplished by assessing the proposed solutions against the goals of the organization, reviewing compliance with legal issues, and verifying the as-is assessment results. This is outlined in the COBIT 2019 Framework, which provides guidance on enterprise governance of information and technology (EGIT). This includes determining the IT capabilities needed to meet the organization's objectives and assessing the proposed solutions against those needs [1]. Additionally, the framework provides guidance on how to review compliance with legal issues and verify the as-is assessment results.
According to ISACA COBIT 2019, the primary role of business leadership in defining the future state of a business case is to assess the proposed solutions against the defined goals and ensure alignment with the overall business strategy. This involves evaluating the feasibility and viability of the proposed solutions and ensuring that they support the achievement of the organization's objectives. Business leaders are responsible for ensuring that the solutions proposed are in line with the organization's strategy, mission, and vision, and that they are adequately supported by the necessary resources.