Showing your ads on top of the mobile page in search results is beneficial because:

Showing your ads on top of the mobile page in search results is beneficial because:

• A) Ads above the results get more prominent notice with desktop screens. There are also no ads on the right-hand side of the results on mobile
• B) Ads below the results get more prominent notice with smaller mobile screens. There are also ads on the right-hand side of the results on mobile
• C) Ads above the results might get more prominent notice with smaller mobile screens. There are also no ads on the right-hand side of the results on mobile
• D) Ads above the results get more prominent notice with larger mobile screens. There are also no ads on the right-hand side of the results on mobile

The correct answer is:

• C) Ads above the results might get more prominent notice with smaller mobile screens. There are also no ads on the right-hand side of the results on mobile

Explanation: Bid your ads to the top of search results on mobile, as that’s where the vast majority of clicks are generated. Because, Ads above the results get more prominent notice with smaller mobile screens. There are also no ads on the right-hand side of the results on mobile.

Read more here: https://services.google.com/fh/files/blogs/google-mobile-ppc-checklist.pdf