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

Which of the following definitions best describes the instance 'pT1a (lung)'?

A. A pathologic primary tumor stage for lung according to AJCC 7th edition indicating that the tumor is 3 cm or less in greatest dimension, surrounded by lung or visceral pleura without bronchoscopic evidence of invasion more proximal than the lobar bronchus (i.e., not in the main bronchus).
B. A pathologic primary tumor stage for lung according to AJCC 7th edition indicating carcinoma in situ.
C. A pathologic primary tumor stage for lung according to AJCC 7th edition indicating that the tumor of any size that invades any of the following: mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, carina or there is separate tumor nodule(s) in a different ipsilateral lobe to that of the primary.
D. A pathologic primary tumor stage for lung according to AJCC 7th edition indicating that the tumor is 2 cm or less in greatest dimension.

Answer: A pathologic primary tumor stage for lung according to AJCC 7th edition indicating that the tumor is 2 cm or less in greatest dimension.