What does a t test specifically aim to evaluate in a hypothesis testing scenario? a. The overall average of two combined groups. b. The variance within a single group. c. The difference between the means of two groups. d. The correlation between two variables.Which of the following best defines a Type II error in the context of hypothesis testing? a. Failing to reject the null hypothesis when it is false. b. Rejecting the null hypothesis when it is true. c. Accepting the null hypothesis when it is true. d. Correctly rejecting the null hypothesis when it is false