Answer:
C) an internal information search
Explanation:
There is a model related to consumer decision making. There are several steps to it.
The first step is
Information search: We think that what are the alternatives or another way to solve the problem. For example, you will buy a new car, repair your car, drive a bus or ride a bicycle to reach your work.
Thus here Robin used internal information research to buy toothpaste or a mouthwash.