What should you use?

You need to identify the root cause of the data refresh issue.

What should you use?
A . the Usage Metrics Report in powerbi.com
B. Query Diagnostics in Power Query Editor
C. Performance analyzer in Power Bl Desktop

Answer: B

Explanation:

Users indicate that the data in Power BI reports is stale. You discover that the refresh process of the Power BI model occasionally times out.

With Query Diagnostics, you can achieve a better understanding of what Power Query is doing at authoring and at refresh time in Power BI Desktop. While we’ll be expanding on this feature in the future, including adding the ability to use it during full refreshes, at this time you can use it to understand what sort of queries you’re emitting, what slowdowns you might run into during authoring refresh, and what kind of background events are happening.

Reference: https://docs.microsoft.com/en-us/power-query/querydiagnostics