Which of the following is an example of synchronous communication?

A) Mail and package delivery
B) Fax
C) Audio conference
D) RSS feed
E) Project log

Synchronous communication involves real-time interaction between individuals or groups. Audio conference is an example of synchronous communication where participants communicate in real-time through audio channels. Mail and package delivery, Fax, RSS feed and Project log are all examples of asynchronous communication which do not require real-time interaction.