A researcher measures a 95% CI of 12 to 16. If the null hypothesis is that the mean value is 10, then what is the effect size for this confidence

A researcher measures a 95% CI of 12 to 16. If the null hypothesis is that the mean value is 10, then what is the effect size for this confidence interval?

(a) None; it doesn't make sense to compute effect size using a CI

(b) Scores shifted 2 to 6 points in the population

(c) Scores shifted 12 to 16 points in the population (d) Scores shifted 4 to 6 points in the population