Which of the following is NOT one of Roter et al.'s categories of communication?

The deeper stages of NREM sleep are characterized by:

a. slow, rolling eye movements. b. highly vivid, unrealistic dreams. c slow brain waves called delta waves. d. muscle paralysis.

Compared to the independent t, the paired t, on data which are really

correlated, is a. a less powerful test b. a more powerful test c. equal in power with the independent t d. none of these, since power is never a function of which statistical test is being used