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

Which of the following definitions best describes the instance 'pN2a (colon)'?

A. A pathologic lymph node stage for colon and rectum according to AJCC 7th edition indicating metastasis in 1 regional lymph node.
B. A pathologic lymph node stage for colon and rectum according to AJCC 7th edition indicating metastasis in 1-3 regional lymph nodes.
C. A pathologic lymph node stage for colon and rectum according to AJCC 7th edition indicating metastasis in 4 to 6 regional lymph nodes.
D. A pathologic lymph node stage for colon and rectum according to AJCC 7th edition indicating metastasis in 7 or more regional lymph nodes.

Answer: A pathologic lymph node stage for colon and rectum according to AJCC 7th edition indicating metastasis in 4 to 6 regional lymph nodes.