During Childbirth,the Hormone Oxytocin Causes Uterine Contractions

Multiple Choice

During childbirth,the hormone oxytocin causes uterine contractions.These contractions move the baby toward the birth canal (vagina) ,where it pushes on pressure-sensing receptors.These receptors signal the mother's hypothalamus to produce more oxytocin,which in turn increases the uterine contractions.This is an example of

A) gene regulation.
B) positive feedback.
C) a cellular-level system.
D) a computational model.
E) negative feedback.