In the United States there is strong relationship between smoking and education with well-educated people less likely to smoke. A study in France included sample of 459 men who were chose at random from men who had visited health center for routine checkup. Education is classified in three categories corresponding to highest level of education as well as smoking status is classified in four categories.
The proportion of men with the primary school education which are nonsmokers is
a. 0.38.
b. 0.58.
c. 0.12.
d. 0.30.