Fundamental to the process of evolution is genetic variation on which selective forces can act in order for change to
occur. Consider the mechanisms listed below. ALL BUT ONE is a mechanism for genetic variation. That is

Which of these internal feedback reactions does not need your brain? oa. your leg jumping when it is hit by a reflex hammer b. your deeper breathing when you need more oxygen c. your body temperature rising when you have an infection d. your heart beating faster when you are in danger