Assertion : Tobacco has been used for human beings for more than four centuries.
Reason : smoking is associated with increased incidences of cancers of lung, urinary bladder and throat bronchitis emphysema , coronary heart disease gastric ulcer. etc,
A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.