system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
In a coho study nonsmokers were found to have carcinoma lung. This indicates -
assistant
The correct answer is  Ans. is 'b' i.e., Etiology for lung Ca is multifactorialo Smoking is not specific for lung cancer becausei) Not everyone who developed lung cancer has smoked --> Other etiological factors (other than smoking) are also involved in causation of lung cancer, i.e., etiology of lung Ca is multifactorial.Not everyone who smoke develops lung cancer.