Take context from the input text and decide on the accurate relationship between 'Facebook' and 'Mark Zuckerberg' from the options provided.
Options: founded by, operator, member of, owned by

John Chambers, the chief executive of Cisco, may not be as recognisable a name as Mark Zuckerberg or Jack Dorsey of Twitter (Xetra: A1W6XZ - news ) , but when he took charge of the networking equipment giant in 1995 the future bosses of Twitter and Facebook (NasdaqGS: FB - news ) were still in school.
founded by