An independent research firm conducted a study of 100 randomly selected children who were → participating in a program advertised to improve mathematics skills. The results showed no statistically significant improvement in mathematics skills, using a=0.05. The program sponsors complained that the study had insufficient statistical power. Assuming that the program is effective, which of the following would be an appropriate method for increasing power in this context (A) Use a two-sided test instead of a one-sided test. (B) Use a one-sided test instead of a two-sided test. (C) Use a=0.01 instead of a= 0.05. (D) Decrease the sample size to 50 children. (E) Increase the sample size to 200 children.