A Researcher Is Concerned About the Power of a Study

A researcher is concerned about the power of a study. The researcher's planned interventional study examines the effect upon depression of instituting twice-yearly trips with the Road Scholar travel program for widows and widowers who have, 1 to 2 years before, lost a spouse to a long illness. What strategies could make Type II error less likely?

A) Decreasing the effect size
B) Increasing the alpha from 0.05 to 0.10
C) Increasing the beta from 0.20 to 0.30
D) Decreasing the beta from 0.20 to 0.10
E) Decreasing the alpha from 0.05 to 0.025
F) Increasing the sample size