<s>[INST] context: Resection of metastases of lung, liver, and brain can result in occasional 5-year cures. In general, surgery should be undertaken only when the primary tumor is controlled, diffuse metastatic disease has been ruled out, and the affected patient's condition and the location of the metastasis permit safe resection. Five-year survival rates as high as 18% have been reported for selected patients with liver metastases from colorectal primary tumors. However, the best results have come from resection of pulmonary metastases, in which 5-year survival rates exceed those of resection for primary bronchogenic carcinoma. Autopsy reviews have demonstrated that many patients with pulmonary metastases have no other evidence of tumor, which suggests that resectional treatment may be justified even when the lung foci are not solitary. Selection of patients for pulmonary resections may be aided by measurement of tumor doubling times; patients with doubling times greater than 40 days appear to benefit most, while those with doubling times less than 20 days are not significantly helped. [/INST] question: Five-year survival rates in excess of 20% may be expected following resection of pulmonary metastases if | options: A: Other organ metastases are present B: Lung lesions are solitary C: Local tumor recurrence is found D: The tumor doubling time is less than 20 days | answer: B </s>