Study the following statements and choose the correct option :
(i) The placenta facilitates the supply of oxygen and nutrients to the embryo.
(ii) Hormones like human chorionic gonadotropin (hCG), human placental lactogen (hPL). estrogens, progesterone only secreted by pregnant female.
(iii) During pregnancy the levels of hormones like estrogens, progesterone, cortisol, prolactin, thyroxine, etc., are increased several folds in the maternal blood.
(iv) The signals for parturition originate only from the placenta which induce mild uterine contractions called foetal ejection reflex.
(v) Foetal ejection reflex triggers release of oxytocin from the maternal pituitary.