Mary, Who Is Six Months Pregnant, Goes to Her Obstetrician

Multiple Choice

Mary, who is six months pregnant, goes to her obstetrician for a test to check the development of her fetus. She uses a device that employs sound waves to produce an image of the fetus. This technique is known as

A) an X-ray.
B) a CT scan.
C) an MRI.
D) an ultrasound.
E) radiography.