Microsoft is now showing why it selects or chooses to show a specific ad directly in the Bing search results. When you click on the arrow down by the URL of the search ad snippet, you will get window dialog that may explain why the ad was shown.
When I try it, Bing shows me "Learn how your ads are chosen" but doesn't show me any more details but when Khushal Bherwani shows it, it gives the full details including Why you're seeing this ad and the advertiser details.
Here is what Khushal Bherwani posted on X:
Here is what I see:
Google does a similar thing as well, by the way.
Forum discussion at X.