When Assessing the Relative Advantages and Disadvantages of Internal and External

When assessing the relative advantages and disadvantages of internal and external electronic fetal monitoring,nurses should be aware that which of the following applies to both types?

A) They can be used when membranes are intact.
B) They measure the frequency, duration, and intensity of uterine contractions.
C) They rely on the woman to indicate when uterine activity ( UA ) is occurring.
D) They can be used during the antepartum and intrapartum periods.