The correct option is B Release of oxytocin from maternal pituitary
Foetal ejection reflex occurs at the time of parturition and are gentle uterine contactions produced by the placenta. This may occur due to extremely high levels of adrenaline during childbirth. Since parturition is a neuro-endocrine process, oxytocin is released by the neurohypophysis of maternal pituitary which stimulates stronger contractions of the uterus and induces labour pain, with decreasing progesterone levels and marks the end of the gestation period. Hence, the correct answer is 'Release of oxytocin from maternal pituitary'.