a. Make a Type I error, that is, to conclude that there is an effect when there actually isn't an effect.
b. Make a Type I error, that is, to conclude that there is no effect when there actually is an effect.
c. Make a Type II error, that is, to conclude that there is no effect when there actually is an effect.
d. Make a Type II error, that is, to conclude that there is an effect when there actually isn't an effect.