<prompt> Ovarian tumors commonly arise from:StromaSurface epitheliumGerminal epitheliumEndoderm  <response>: Ans. is b, i.e. Surface epitheliumRef: Shaw 14thed, p334Epithelial tumors are derived from the ovarian surface epithelium. In general, epithelial tumors comprise 50-60 of all ovarian tumors but malignant epithelial tumors comprise 90 of all ovarian cancers. 