Evaluating control effectiveness requires determining whether the control is appropriately designed to address the relevant risk and whether it operates as intended in practice. A well-designed control that is not consistently performed cannot be considered fully effective, while a consistently performed control with an inadequate design may still fail to mitigate the relevant risk. Options A, C, and D primarily address efficiency or cost-effectiveness rather than effectiveness. Delays, duplication of effort, required resources, and control cost may indicate opportunities for process improvement, but they do not establish whether the control achieves its intended objective. Internal audit therefore evaluates both design adequacy and operating effectiveness when determining whether a control appropriately mitigates risk. Consequently, option B provides the most complete assessment of control effectiveness.