A data analyst needs to present the results of an online marketing campaign to the marketing manager. The manager wants to see the most important KPIs and measure the return on marketing investment. Which of the following should the data analyst use to BEST communicate this information to the manager?

A. A real-time monitor that allows the manager to view performance the day the campaign was launched
B. A sell-service dashboard that allows the manager to look at the company's annual budget performance
C. A spreadsheet of the raw data from all marketing campaigns and channels
D. A summary with statistics, conclusions, and recommendations from the data analyst