8) The diagnostic criteria for chronic bronchitis should be cough and expectoration() A) They occur for at least 3 months each year and last for more than 10 yearsB) They occur for at least 1 months...

8) The diagnostic criteria for chronic bronchitis should be cough and expectoration() A) They occur for at least 3 months each year and last for more than 10 years B) They occur for at least 1 months each year and last for more than 2 years C) They occur for at least 2 months each year and last for more3 years D) They occur for at least 3 months each year and last for more than 2 years E) They occur for at least 6 months each year and last for more than 4 years