3. (8.32) Oligofructose and calcium absorption. C. Nondigestible oligosaccharides are known to stimulate calcium absorption in rats. A double-blind, randomized experiment investigated whether the consumption of Oligofructose similarly stimulates calcium absorption in 11 healthy male adolescents 14 to 16 years old. The subjects took a pill for nine days and had their calcium absorption tested on the last day. The experiment was repeated three weeks later. Some subjects received the Oligofructose pill in the first round and then a pill containing sucrose (serving as a control) in the second round. The order was switched for the remaining subjects. What are the explanatory and response variables here? What design was used in this experiment? Why was the order of treatment switched for some subjects? The study was double~blind. What does this mean