Task: Question Answering
Input (English): Background Paragraph: During Amniocentesis a small amount of amniotic fluid, which contains fetal cells, is extracted from the amnion or amniotic sac surrounding a developing fetus, and the fetal DNA is examined for genetic abnormalities. Amniocentesis is not performed for every pregnancy, but is generally done when an increased risk of genetic defects in the fetus is indicated, by mother's age (over 35 years is common), family history of genetic defects, or other factors. 
Story: David is a doctor with the city hospital. Today, he is seeing four patients, patient A, patient B, patient C, and patient D. All four patients are expectant mothers. Moreover, patient A is over thirty five years old, but patient B is under thirty five years old. Patient C has family history of genetic disorder, but patient D does not have any family history of genetic disorder. David needs to prescribe appropriate treatment according to each patient's condition. 
Question: Which patient would be more at risk of genetic defects in the fetus, patient C or patient D?
Output (English): patient C.