A 28-year-old female presents to her general practitioner with morning nausea and vomiting, weight gain, and two missed menstrual cycles. The physician orders a pregnancy test. What chemical in the urine does this lab test detect?
A. alpha-fetoprotein
B. creatine phosphokinase
C. carcinoembryonic antigen
D. human chorionic gonadotropin
Answer: A