A 20-year-old female presents for an infertility workup. She has never had a menstrual period. She is short with a broad chest, webbed neck, and low-set ears. It is demonstrated that she has an abnormal karyotype.The cause of the woman's abnormal karyotype is which one of the following?
Maternal nondisjunction Paternal nondisjunction Both maternal and paternal nondisjunction Either maternal or paternal nondisjunction