You have formulated a hypothesis: "Blueberries contain more vitamin C than raspberries." To test your hypothesis you measure vitamin C levels in 20 blueberries and 20 raspberries from bushes that were grown in the same area under the same environmental conditions (temperature, rain, sunlight). What is the dependent variable in this experiment?

(A) The type of soil, temperature, amount of rain and sunlight in the area
(B) Vitamin C levels
(C) Blueberries
(D) Raspberries