Answer: Improve the ad’s quality score.
Step-by-step explanation:
Rina should try to improve her ad's quality score because even if you pay for an ad, it is not a guarantee that your ad will be picked if it does not have a good quality score.
There will be other people like her who have paid for ads and if hers is not as high quality as theirs, the search engine's search bots will pick those ones up more which would leave her ads lower on the ad hierarchy.
She can try to improve ad quality by including relevant ads and giving users a better landing page experience.