Amy Is Being Subjected to the Strange Situation (Attachment-Based Situation

Amy is being subjected to The Strange Situation (attachment-based situation where she is observed through a glass mirror and is separated from her mother to then be reunited with her again) . It is based on behaviours that are observed through:

A) natural-setting observations.
B) laboratory-setting observations.
C) interviews of those knowledgeable about the baby's behaviour.
D) all of the above