When you log into a website that uses a directory service, what command authenticates your username and password?.

Linkedin is similar to other social media platforms, because you can communicate with other users of the website, talk to owners of companies, or even employees, on the other hand it is different because you can't follow there profile, for it is strictly used for businesses.hope this !

1: is a. 2: is  d. 3: is b.

Same issue happened to me i had 4/5 and suddenly they went down to 3/5 .the reason must be that the question u recived a brainliest answer mark, was deleted by a moderator. they can delete a question for some reason if it isn't complete or has been reported. so there for that is most likely the reason.best of hope u earn another one

C. building block is correctgood luck