Cessation of menstruation (secondary amenorrhoea) may occur because of

A. True Psychological stress affects hypothalamic activity.

B. True Amenorrhoea is common during starvation.

C. True Continuous progesterone administration can have the same effect.

D. True Androgens from the tumour may oppose the effects of female sex hormones on the endometrium.

E. True Normally GnRH secretion is pulsatile; thus interference with the normal hormone rhythms can cause amenorrhoea and infertility.