Answer:
C. 2
Step-by-step explanation:
Cohen's d is a parameter used to express the standardised difference between two means. It is defined as the difference between the means divided by the pooled standard deviation.
In this case, the difference between both means (M2-M1) is 8. As for the pooled standard deviation, simply take the square root of the given pooled variance:
Therefore, the value of Cohen's d (d) is: