Which statement is incorrect with regards to dysfunctional uterine bleeding

• A. it is very rare in the teenage years
• B. it is usually due to anovulatory cycles
• C. oestrogen is used acutely to slow bleeding by contracting the uterine arteries
• D. cyclical progesterone is used if it is a chronic problem
• E. in patients over 35 years endometrail biopsy should precede oetrogen administration