An 8-year-old thoroughbred mare is evaluated for a 1-year history of infertility and atypical aggressive behavior. Physical exam bindings are normal except for an enlarged ovary discovered on rectal palpation. Ultrasonography demonstrates a multiloculated appearance of the enlarged ovary. Which of the following assays, when elevated, is the most consistent indicator of the presumptive diagnosis?
a. Progesterone
b. Estrogen
c. Testosterone
d. FSH
e. Inhibin
Answer/E