Which of the Following Statements About Obstetric-Gynecologic Sonography Is Untrue

Which of the following statements about obstetric-gynecologic sonography is untrue?

A) Transvaginal sonography (TVS) usually provides better resolution during the third trimester.
B) Transabdominal probes placed on the anterior abdominal wall or perineum use frequencies of 3.5 MHz or higher, depending on body habitus.
C) Transvaginal probes are closer to the area of interest, so higher frequency transducers are used (5.0 MHz or higher) .
D) Sonography is the preferred imaging modality for the female pelvis, mainly because it is nonionizing.