A 39 year old women,gravida 3,para 3,complains of severe,progressive secondary dysmenorrhoea and menorrhagia.Pelvic examination demonstrates a tended,diffusely enlarged uterus with no adnexal tenderness.Results of endometrial biopsy are normal.This patient most likely has:

• A. Endometriosis
• B. Adenomyosis
• C. Endometritis
• D. Leiomyoma