Astudy that conducts interviews with mothers of extreme multiple births such a sextuplets is what kind of case study

A study that conducts interviews with mothers of extreme multiple births such a sextuplets is what kind of case study? Case study interviews.

There are many types of case studies, when interviewing people who meet the criteria of being able to give insight to a topic, you are conducing a case study interview. You are interviewing the person or persons' to gain knowledge from their experiences. 

disorders of the brain include both behavior disorders and other psychiatric illnesses. the primary difference between a behavior disorder and another type of psychiatric disorder is the presence of choice. psychiatric conditions are considered to be involuntary while in behavior disorders, choices are essential.

i truly dont know the answer wait i do its 1,3,4