High-quality data should primarily be:

High-quality data is essential for effective decision-making, and it encompasses several critical attributes. While timeliness is indeed an essential factor, the other attributes, namely comprehensiveness and accessibility, also contribute significantly to the overall quality of data.

Timely data ensures that the information is relevant and reflects the current state of affairs, allowing decision-makers to act based on the most recent and accurate data available. Comprehensive data covers all necessary aspects and variables, providing a complete picture that leads to well-informed conclusions. Accessibility refers to how easily stakeholders can obtain and utilize the data for their analysis, which is crucial for operational efficiency and informed decision-making.

Given that high-quality data embodies all these characteristics, the most accurate understanding aligns with the option that includes all of them. Thus, the correct answer is that high-quality data should be timely, comprehensive, and accessible. Each of these factors plays a key role in ensuring the data's effectiveness in guiding decisions.