You have formulated a hypothesis: "Mangos contain more vitamin C than oranges." To test your hypothesis you measure vitamin C levels in 20 oranges and 20 mangos from trees that were grown in the same orchard under the same environmental conditions (temperature, rain, sunlight). What is the independent variable in this experiment? Question options:
A) The amount of rain and sunlight the trees received
B) Vitamin C levels
C) The type of fruit
D) The type of soil the trees grew in