The Nurse Explains That a Woman Who Uses Oral Hypoglycemic

The nurse explains that a woman who uses oral hypoglycemic agents to control diabetes mellitus will need to take insulin during pregnancy because:

A) insulin can cross the placental barrier to the fetus.
B) insulin does not cross the placental barrier to the fetus.
C) oral agents do not cross the placenta.
D) oral agents are not sufficient to meet maternal insulin needs.