For each user who comes to your site, Google Analytics automatically captures which of the following Traffic Source dimensions.

  • Source, medium, campaign and Ad content.
  • Source and Medium
  • Campaign and Ad Content
  • Campaign and medium

The Correct Answer is:

  • Source, medium, campaign and Ad content.

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You can read more here: https://support.google.com/analytics/answer/1033173?hl=en