Answer:
PERFUME
Explanation:
In an experiment, the independent variable is the variable that is changed or manipulated by the experimenter in order to effect a measurable response in the dependent variable.
In this experiment, Johanna is trying to investigate the response of bees to five different perfumes- Ralph Lauren, Armani, Mark Jacobs, Vera Wang, and an odorless liquid, which is the control. Hence, the PERFUME is the independent variable because it is the manipulated variable.