1.     Which of the following situations involving a pregnant mother would involve a dangerous cross-reaction of blood types?

a.      if the mother was A+ and the baby was A-

b.     if the mother was A-, and the baby was A+, and the mom was previously sensitized.

c.      if the mom was A+ and the baby was AB+

d.     if the mom was B- and the baby was AB-, and the mom was previously sensitized.