Explanation
(A) LOA identifies a fetus whose back is on its mother's left side, whose head is the presenting part, and whose back is toward its mother's anterior. It is easiest to auscultate fetal heart tones (FHTs) through the fetus's back. (B) The identified fetus's back is on its mother's left side, not right side. It is easiest to auscultate FHTs through the fetus's back. (C) In an LOA position, the fetus's head is presenting with the back to the left anterior side of the mother. The umbilicus is too high of a landmark for auscultating the fetus's heart rate through its back. (D) This is the correct auscultation point for a fetus in the left sacroanterior position, where the sacrum is presenting, not LOA.