69. 最常見之後腹腔惡性腫瘤為:(A)惡性纖維性組織瘤(malignant fibrous histiocytoma)(B)平滑肌肉瘤(leiomyosarcoma)(C)神經性肉瘤(neural sarcoma)(D)脂肪肉瘤(liposarcoma)