Explanation:
Classification of assets needs to be undertaken to determine sensitivity of assets in terms of risk to the business operation so that proportional countermeasures can be effectively implemented. While higher costs are allowable to protect sensitive assets, and it is always reasonable to minimize the costs of controls, it is most important that the controls and countermeasures are commensurate to the risk since this will justify the costs. Choice B is important but it is an incomplete answer because it does not factor in risk. Therefore, choice D is the most important.