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

Which of the following definitions best describes the instance 'pN1a (colon)'?

A. A pathologic lymph node stage for colon and rectum according to AJCC 7th edition indicating metastasis in 7 or more regional lymph nodes.
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 tumor deposit(s), i.e., satellites in the subserosa, or in non-peritonealized pericolic or perirectal soft tissue without regional lymph node metastasis.
D. A pathologic lymph node stage for colon and rectum according to AJCC 7th edition indicating metastasis in 1 regional lymph node.

Answer: A pathologic lymph node stage for colon and rectum according to AJCC 7th edition indicating metastasis in 1 regional lymph node.