The Observation Method of Gathering Research Is Most Effective For

The observation method of gathering research is most effective for:

A) deciding whether to package dog food in a green or a brown bag.
B) proving that the ad copy for a all-natural baby food communicated effectively with its target market.
C) identifying the target markets for an air refresher.
D) determining how people act while waiting in a bank line.
E) determining the potential success rate of cellular phone weighing just three ounces.