In a Study of Alcohol and Oral Cancer the Crude

Multiple Choice

In a study of alcohol and oral cancer the crude relative risk is 4.0 overall but it is 2.0 for men and 2.0 for women when the sexes are considered separately.This suggests
That:

A) There is confounding by sex in these data
B) There is confounding by some unknown or unmeasured factor in these data
C) There is evidence of effect modification by sex in these data
D) The results have been adjusted for age and sex
E) The results are due to bias