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

Which of the following definitions best describes the instance 'pT0 (colon)'?

A. A pathologic primary tumor stage for colon and rectum according to AJCC 7th edition indicating that there is no evidence of primary tumor.
B. A pathologic primary tumor stage for colon and rectum according to AJCC 7th edition indicating that the tumor directly invades other organs or structures.
C. A pathologic primary tumor stage for colon and rectum according to AJCC 7th edition indicating that the tumor invades subserosa or into non-peritionealized pericolic or perirectal tissues.
D. A pathologic primary tumor stage for colon and rectum according to AJCC 7th edition indicating that the tumor perforates visceral peritoneum.

Answer: A pathologic primary tumor stage for colon and rectum according to AJCC 7th edition indicating that there is no evidence of primary tumor.