I think it will be E.
Observation: When an adult is present, children are more likely to share toys with their siblings than non-siblings.
Inference: Children are more inclined to share with family members when they feel they are being observed by an authority figure.
Objective: Finding which option, if true, would
strengthen the argument as per the following
condition: during the study,
the children exhibited increased sharing behavior when: (this is very important because the answer depends on it. Thus adding it before every option helps in finding out our answer).
A. the toys in the room were new to the children, rather than toys they had previously played with at home.During the study, the children exhibited increased sharing behavior when the toys in the room were new to the children, rather than toys they had previously played with at home.
If this is true, then in no way does it strengthen our inference that children are more inclined to share with family members when an authority figure is present. So
eliminate.
B. the observing adult was a parent of the siblings, rather than a stranger or non-relative adult.
During the study, the children exhibited increased sharing behavior when the observing adult was a parent of the siblings, rather than a stranger or non-relative adult.
This does look appealing in some ways but if you look closely, it doesn't address anything related to our inference. Ask yourself, how does it strengthen our inference that children are more inclined to share with family members when being watched by an adult? Sure, this option addresses the authority figure but our inference is not about that.
Eliminate C. the siblings were younger and appeared to need help understanding how to use the toys, compared to non-siblings who were adept at using the toys.
During the study, the children exhibited increased sharing behavior when the siblings were younger and appeared to need help understanding how to use the toys, compared to non-siblings who were adept at using the toys.
So they needed help from their siblings and thus shared their toys. Doesn't strengthen the inference that they shared with their family members when being watched by an adult.
EliminateD. the room had more toys available than usual, making it easier for children to find and share multiple toys.
During the study, the children exhibited increased sharing behavior when the room had more toys available than usual, making it easier for children to find and share multiple toys.
Simply reading it together tells us that it's not correct. Room had more toys, thus they shared. Not what we are looking for.
EliminateE. the adult explicitly encouraged the children to share, regardless of whether the other child was a sibling or a non-sibling.
During the study, the children exhibited increased sharing behavior when the adult explicitly encouraged the children to share, regardless of whether the other child was a sibling or a non-sibling.
This means that despite equal encouragement to share with both siblings and non-siblings, the observed behavior was that children shared more with siblings. This directly supports the psychologist's argument that children have a natural inclination to share more with family members when being observed by an authority figure.