2. Regarding ovarian dysgerminomas, which of the following is (are) true?

A) A combination of surgery and chemotherapy is the primary mode of therapy.
B) This tumor occurs predominantly in women younger than 30 years of age.
C) Dysgerminoma and serous cystadenoma are the two most common ovarian neoplasms of pregnancy.
D) Sonographically, dysgerminomas are solid masses that are predominantly echogenic.
E) The serum a-fetoprotein level is elevated.