11. If you had confidence intervals for two groups which did not overlap what could you reasonably conclude?

a) That there was unlikely to be a difference between the means of the two groups in the population

b) That there was unlikely to be a difference in the variability of two groups in the population

c) That there was likely to be a difference between the means of the two groups in the population

d) That there was likely to be a difference in the variability of the two groups in the population