The Placebo Research Group conducted a study to find the extent of placebo effects. A group of men randomly selected were asked to take a test before and after taking a pill that induces a mild headache. The pill in half of the randomly selected men was replaced with a similar pill that has no effect. For each trial, researchers recorded the change in time men took to complete the tests before and after taking the pill. Describe the explanatory and response variable in this study. What are the treatments? Identify any lurking variables that could interfere with this study. Is it possible to use blinding in this study