A group of 2000 people signed up for a study that measured the effects of a new weight loss medication. The study noted that the medication might work differently in men than in women. The study planned to use an established weight loss medication, the new medication, and a fake treatment that contained no medication. Identify the response and explanatory variables in this experiment. O Explanatory: how much weight is lost; Response: weight loss medication O Explanatory: Gender; Response: how much weight is lost O Explanatory: how much weight is lost; response: gender Explanatory: weight loss medication; Response: how much weight is lost