This is easy, the answer is: <span>Ø</span>
<span>Example of Trisomy 21 detected</span>... <span>the presence , which is found in Down syndrome, is calledtrisomy 21.</span> ... <span>Of these, Trisomy 21 and Trisomy 18 are the most common.</span> ... <span>XXX (Triple X syndrome); XXY (Klinefelter syndrome); XYY</span> ... <span>Turner syndrome (XO).
so i think all are right</span>