a) I am not certain what is meant by "what corresponds to the criterion of the test?", but my guess is a redneck scoring greater than 80% and a non-redneck scoring 80% or below correspond to the criterion of the test.
b) An (actual) redneck who scores 80% or lower.
c) A non-redneck who scores greater than 80%.
d) Power is given by 1 minus the probability of a Type II Error. So, everything that is NOT a Type II Error corresponds to the power of the test. In this case, a redneck who scores above 80%, or any non-redneck (regardless of outcome) correspond to the power of the test.
Please refer to my chart, if it helps.