A researcher predicts that a treatment will increase scores. To test the treatment effect, a sample of n 5 16 is selected from a population with m 5 80 and a treatment is administered to the individuals in the sample. After treatment, the sample mean is M 5 78 with s 2 5 16.

If the researcher uses a one-tailed test with a 5 .05, then what decision should be made?

a. Reject H0 with a 5 .05 or with a 5 .01

b. Fail to reject H0 with a 5 .05 or with a 5 .01

c. Reject H0 with a 5 .05 but not with a 5 .01

d. Reject H0 with a 5 .01 but not with a 5 .05