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

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

A. A histologic grade for ovarian tumor according to a two-tier grading system indicating that the tumor is high grade.
B. A histologic grade for ovarian tumor according to a two-tier grading system indicating that the tumor is low grade.
C. A frequency unit which is equal to 1 complete cycle of a recurring phenomenon in 1 second.
D. A pathologic primary tumor stage for kidney according to AJCC 7th edition indicating that the tumor is 7 cm or less in greatest dimension and limited to the kidney.

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