A Research Study Compares the Risk of Lung Disease for Men

A research study compares the risk of lung disease for men who smoke to the risk of lung disease for women who smoke. The sample relative risk is 1.1 and a 95% confidence interval for the relative risk is 0.5 to 1.9. Which of the following statements is most correct about the comparison of the two groups?

A) The population risks may be the same because the interval includes the value 1.
B) The population risks may be the same because the interval doesn't include the value 0.
C) The population risks might differ because the interval includes the value 1.
D) The population risks might differ because the interval doesn't include the value 0.