<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 36-year-old G4P0A3 woman presents at the prenatal diagnostic center at 18 weeks of gestation for the scheduled fetal anomaly scan. The patients past medical history reveals spontaneous abortions. She reports that her 1st, 2nd, and 3rd pregnancy losses occurred at 8, 10, and 12 weeks of gestation, respectively. Ultrasonography indicates a female fetus with cystic hygroma measuring 4 cm x 5 cm in size and fetal hydrops. Which of the following karyotypes does her fetus most likely carry?? A: Trisomy 21, B: Trisomy 18, C: Monosomy 18, D: Trisomy 13, E: 45 X0,  <response>: This is a question about identifying the most likely karyotype in a fetus with certain ultrasound findings. The key findings in the question stem are cystic hygroma, fetal hydrops, and a history of multiple first trimester pregnancy losses. Cystic hygroma and fetal hydrops are classic ultrasound findings in Turner syndrome 45 X0. Turner syndrome is also associated with increased risk of first trimester pregnancy loss. Trisomy 21, 18 and 13 can be associated with cystic hygroma and hydrops but are less likely given the history of recurrent early pregnancy loss. Monosomy 18 is not viable.E: 45 X0 