Which among the following is the MOST common congenital uterine malformation that causes recurrent aboions?

Anatomical abnormalities are responsible for 10-15% of recurrent aboion. Congenital and acquired anomalies. Congenital anomalies are due to defects in the Mullerian duct fusion or resorption (e.g. unicornuate, bicornuate, septate or double uterus). This causes about 12% cases of recurrent aboions. Acquired anomalies are, Intrauterine adhesions Uterine fibroids Endometrosis Cervical incompetence Ref: Textbook of Obstetrics by D C Dutta, 6th edition, Page 169.