Conversion Tracking helps you improve the return on investment (ROI) from your online advertising because it:

Conversion Tracking helps you improve the return on investment (ROI) from your online advertising because it:

  • measures trends relating to the search terms people have used before seeing your ad
  • focuses on getting customers to complete an online purchase
  • shows you which ads lead to customer actions that have value for your business
  • automatically gives you personal details about the people who convert

Correct answer is:

shows you which ads lead to customer actions that have value for your business

Explanation: Conversion tracking is a free tool that shows you what happens after a customer clicks on your ads — whether they purchased a product, signed up for your newsletter, called your business, or downloaded your app. When a customer completes an action that you’ve defined as valuable, these customer actions are called conversions.

Read more here: https://support.google.com/adwords/answer/1722022?hl=en