High quality ratings for an ad can

  • increase its average cost-per-click (avg. CPC) bid
  • be achieved with an increase in bid
  • improve its position
  • increase how often people click on it

The correct answer is:

  • improve its position

Explanation: Quality Score is an estimate of the quality of your ads, keywords, and landing pages. Higher quality ads can lead to lower prices and better ad positions.

Read more here: https://support.google.com/adwords/answer/140351?hl=en