The correct answer is A, which involves using cost allocation tags. These tags are key-value pairs that can be applied to AWS resources, allowing the company to categorize and organize them effectively. By assigning cost allocation tags, the company can gain better insights into its AWS spending, allocate costs based on specific tags, and achieve more accurate cost reporting and analysis. This approach enables better cost management and optimization within the organization. The other options, while important for various aspects of AWS resource management, do not directly address the requirement of labeling resources for cost tracking and categorization.