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

Which of the following definitions best describes the instance 'pN1 (kidney)'?

A. A unit of molarity which is equal to one millionth of a molar or 10^[-6] M.
B. AL 2023-03-05: Improperly created IRI (with 'efo' in the IRI) replaced by the correct form for SWO IRIs.
C. A pathologic lymph node stage for kidney according to AJCC 7th edition indicating that there is regional lymph node metastasis.
D. A pathologic lymph node stage for kidney according to AJCC 7th edition indicating that there is no regional lymph node metastasis.

Answer: A pathologic lymph node stage for kidney according to AJCC 7th edition indicating that there is regional lymph node metastasis.