Task: Instance Description Understanding (ontology: Sciences/Computer_Science)

Which of the following definitions best describes the instance 'Low grade ovarian tumor'?

A. A pathologic lymph node stage for colon and rectum according to AJCC 7th edition indicating metastasis in 1-3 regional lymph nodes.
B. A histologic grade for ovarian tumor according to a two-tier grading system indicating that the tumor is high grade.
C. A volume unit which is equal to one thousandth of a liter or 10^[-3] L, or to 1 cubic centimeter.
D. A histologic grade for ovarian tumor according to a two-tier grading system indicating that the tumor is low grade.

Answer: A histologic grade for ovarian tumor according to a two-tier grading system indicating that the tumor is low grade.