Which level of constraint allows us to draw causal inferences with confidence?

In analyzing data in differential research, if we have score data and two groups, we would typically use

A) A t-test for independent groups. B) An analysis of variance (ANOVA). C) A Mann-Whitney U-Test. D) Either A or B.

Nongovernmental organizations are uncommon and tend to be fairly uniform in their goals and membership

a. True b. False Indicate whether the statement is true or false