The correct answer is D. cookies.
A cookie is a small text file that a website saves on your computer or mobile device when you visit the site. It enables the website to remember your actions and preferences (such as login, language, font size and other display preferences) over a period of time, so you donât have to keep re-entering them whenever you come back to the site or browse from one page to another.
Cookies are used to identify return visitors to a website. When a visitor first visits a website, a cookie is created and stored on the visitor’s computer. The next time the visitor visits the website, the cookie is sent back to the website. The website can then use the cookie to identify the visitor and provide them with a personalized experience.
Logged-in visitors are identified by their username and password. Digital certificates are used to verify the identity of websites and online users. Electronic time stamping is used
to record the date and time of events.I hope this helps! Let me know if you have any other questions.