Medical malpractice action by P against D Utility Co. following the death of X, P's father, from cancer. P' s theory is that D caused X' s cancer by placing high voltage electrical lines too close to X' s residence. D denies that the high voltage lines could have caused X' s cancer. At trial, P wishes to call W, an M.D. engaged in cancer research who holds a faculty position at a major research hospital. If permitted, W will testify that the electromagnetic fields produced by high voltage lines are capable of causing cancer. Assume W's view is held by only a small minority of cancer experts. D objects toP's testimony. How should the court analyze this problem?