A 15-year-old girl with short stature, neck webbing, and sexual infantilism is found to have coarctation of the aorta. A chromosomal analysis likely would demonstrate which of the following?
a) Turner syndrome (45,X)
b) Klinefelter syndrome (47,XXY)
c) Down syndrome (Trisomy 21)
d) Edwards syndrome (Trisomy 18)