Respuesta :
The correct answer is B. The temperature of each aquarium
Explanation:
In an experiment, the independent or manipulated variable is the factor that is controlled by the researcher usually as she/he changes it on purpose to determine the way this affects the main factor that is being studied, which is known as the dependent variable. According to this, in the experiment presented the temperature of each aquarium (Option B) is the independent variable because this is manipulated on purpose by the scientist to understand how this affects the length of the butterfly's life. Also, the length of the butterfly's life is the dependent variable or factor studied.