Some researchers have noted that adolescents who spend a lot of time playing video or computer games are at greater risk for depression and for violence. This is an example of

A. a valid conclusion since more time yields more aggression is a positive association.
B. an observational study with lurking variables that may explain the association.
C. a single-blind experiment because the subjects knew they were watching television.
D. a paired data experiment since we are studying both aggression and TV watching.

B. an observational study with lurking variables that may explain the association.

Step-by-step explanation:

Observational Study is the study involving, collection of sample data, & observing the variations / trends in it, without any experimental manipulation.

The study given tries to observe the impact of computer, video games on depression vulnerability, violence among adolescents. The study observes the natural data of collected sample adolescents, without any experimental changes.

It also has many lurking variables which may effect the independent variables (gaming) & dependent variables (depression & violence). Eg : Parents state of mind & relationship with adolescents, digital medium usage by peer group. As, both given variables might effect the study variables & explain their relationship

i think it would be 42cm

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