Answer:
d. watching footage obtained from cameras set up unobtrusively on various streets
Step-by-step explanation:
A naturalistic observation is a kind of observations done by people especially by the psychologists as well as other social researcher to study and observe their subject in their natural state.
Thus the best way to analyse the driving behavior of the drivers in their natural way is to watch them driving by seeing the video footage obtained from the various cameras set up unobtrusively on the streets
Thus the naturalistic observation study would be
d. watching footage obtained from cameras set up unobtrusively on various streets