Researchers wanted to know if there is a link between proximity to high-tension wires and the rate of leukemia in children. to conduct the study, researchers compared the rate of leukemia for children who lived within 1/2 mile of high-tension wires to the rate of leukemia for children who did not live within 1/2 mile of high-tension wires. the researchers found that the rate of leukemia for children near high-tension wires was higher than the rate for those not near high-tension wires. can the researchers conclude that proximity with high-tension wires causes leukemia in children? a. no, because this is an observational study. b. yes, because this is a designed experiment, which allows for statements of causality. c. no, because this is a designed experiment. d. yes, because this is an observational study, which allows for statements of causality.