The Garden Club of Monck's Corner is conducting a scientific experiment to determine which variety of flower will attract the largest butterfly population. The Garden Club has planted different varieties of flowers in a small garden in front of the town hall to attract the butterflies. The Garden Club will count and record the butterflies on each variety of flower each time they visit the garden. What is the independent variable in the experiment?

A. variety of flowers planted.
B. location of garden
C. size of garden
D. size of butterfly population