Which of the Following Is the First Step in Conducting

Which of the following is the first step in conducting a meta-analysis?

A) computing the statistic d using the formula d = (V1 - V2) /s,where V1 and V2 are the two variables in question and s is the standard deviation
B) locating all previous studies on the question being investigated
C) collecting data on the variability there is from one respondent to the next in the numbers reported
D) identifying the factor that actually causes or influences an outcome