A

Dysgerminomas characteristically secrete lactate dehydrogenase, so they present with isolated LDH elevation while α-fetoprotein and β-hCG remain normal. Yolk-sac tumors raise AFP, malignant teratomas usually lack a consistent marker, and mucinous cystadenocarcinomas are linked more to CA-125/CEA than LDH. Therefore the pattern described fits a dysgerminoma. [Pressley, 1992, PMID 1541442; Awais, 1983, PMID 6823354]