(A) A browser cookie
(B) Artificial intelligence
(C) A randomly-assigned unique identifier
(D) A sequential unique identifier
Google Analytics uses special browser cookies called Analytics cookies and a randomly assigned unique identifier called ClientID to differentiate new and returning users.
The ClientID contains a unique random number to identify a user and a first timestamp which indicates their time of the visit to the website. When a user visits the website then the cookie collects their information and compares it with the data from ClientID and if there is no match then they are recorded as a New user. If there is a match then the user is recorded as a Returning user.
This question is a part of the Assessment 1 section of the Advanced Google Analytics Certification course. You can find the answers with full explanation for the first Assessment in our Advanced Google Analytics Assessment 1 Answers page or you can check out the answers for all the assessment questions in our Advanced Google Analytics Assessment Answers page.