Which of the Following Is NOT a Factor That Limits

Which of the following is NOT a factor that limits the precision with which meta-analysis can estimate a mean effect size?

A) The bias against publishing null results might inflate the Type I error rate in the set of studies being reviewed.
B) The mean effect size can be sensitive to the effect of outliers.
C) There are no generally accepted statistical techniques for conducting meta-analyses.
D) High levels of precision require effect sizes from a large number of studies which may not always be available.