Which of the following is an example of meta$-$analysis?

Multiple Choice

Gall used two studies, each using the same samples and measures, to determine why sales of a product have decilned.

Yeeun used one study, which used a consistent measuring method, to determine the cause of employee stress.

Serglo combined several studies, each using the same measuring method, to determine why profitability has increased.

Fionn combined several studles, each using different kinds of samples and measures, to determine the cause of employee tw

Sosuke used one study, which combined different samples, to determine why customers buy a certaln product.