Q. 37Also... B) what is it's value?

Thirty-six different video games showing violence were observed. The duration times of violence (in seconds) were recorded. When using this sample for a t test of the claim that the population mean is greater than 84 sec, what does df denote, and what is its value? What does df denote? O A. The test statistic O B. The sample size O C. The sample standard deviation O D. The number of degrees of freedom