_______ is defined as an economic resource, a group, a subject of study and a process.

Management is the correct answer as it fits all four definitions mentioned - it's considered an economic resource (human capital), it can be viewed as a group (managerial team), it's a subject of academic study, and it's a process (POC: planning, organizing, commanding, controlling). Business (A) is too narrow, Administration (B) is a subset, and Organisation (D) is the structure, not the dynamic process.