After an Ultrasound, a Client in Labor Is Informed That

After an ultrasound, a client in labor is informed that she has a low-lying placenta. Which of the following statements accurately describes the client's diagnosis?

A) The placenta is improperly implanted in the upper uterine segment.
B) The placenta attaches in the lower uterine segment but it does not reach the cervical os.
C) Only the edge of the placenta extends to the os.
D) The internal os is covered entirely by the placenta.