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

Which of the following definitions best describes the instance 'cM1a (colon)'?

A. A pathologic distant metastases stage for colon according to AJCC 7th edition indicating that metastasis is confined to one organ based on clinical assessment.
B. A pathologic distant metastases stage for colon according to AJCC 7th edition indicating that there is clinical evidence of distant metastases by history, physical examination, imaging studies, or invasive procedures, but without microscopic evidence of the presumed distant metastases.
C. A pathologic distant metastases stage for colon according to AJCC 7th edition indicating that there are no symptoms or signs of distant metastasis.
D. A pathologic distant metastases stage for colon according to AJCC 7th edition indicating that there is microscopic evidence confirming distant metastatic disease.

Answer: A pathologic distant metastases stage for colon according to AJCC 7th edition indicating that metastasis is confined to one organ based on clinical assessment.