Acult in the 1950s believed that the world was coming to an end very soon. researchers leon festinger and his colleagues studied this cult by joining the group and pretending to share these beliefs. what research method were they using? archival analysis ethnography correlational study field experiment

The method researchers Leon Festinger and his colleagues used to study a cult which included joining the group and pretending to share these beliefs was an ethnography research method .
In the etnographic research method researchers observe and/or interact with the study's participants in their real-life environment. 

The jugular vein located, on an animal, starts proximally at the base of the neck and moving towards the head along the jugular groove.