Which of the following represents most dangerous situation_____________?

Which of the following represents most dangerous situation_____________?

A. Rh+ ve mother, who is bearing 2nd Rh+ ve child
B. Rh+ ve mother, bearing her 2nd + ve child
C. Rh+ ve mother, bearing her 1st Rh – ve child
D. Rh – ve mover, bearing her 1stRh + ve child