Which one is not the item of economic cost to the business ?

In managerial economics, implicit costs (often contrasted against explicit accounting costs when defining the imputed opportunity cost component of economic cost) arise from using 'Owner supplied resources'—such as the owner's own capital, land, or entrepreneurial time—which represent non-monetary opportunity costs. By contrast, 'Market supplied resources' are purchased or hired externally for explicit monetary payments and therefore represent explicit accounting costs rather than implicit owner-supplied opportunity costs.