With no explanation, chose the best option from "A", "B", "C" or "D". of other witnesses — attempted to show general causation through both avenues. On appeal, the LeBlanc family only expressly addresses whether benzene causes MMM, and we accordingly limit our review. Dr. Gardner purported to rely on both epidemiological studies and his “clinical experience” in his expert opinion. The district court ruled that neither provided a sufficient basis for his opinion. 1. Epidemiological Studies Simply put, the several studies and reports on which Dr. Gardner purported to rely suffer from common deficiencies that this court in Knight and the Supreme Court in Joiner have explained support a district court’s exclusion of expert testimony- First, some of the studies do not represent statistically significant results. Joiner, 522 U.S. at 145, 118 S.Ct. 512 (<HOLDING>); see also David H. Kaye & David A. Freedman,

A: holding that an experts opinion must be based on facts in evidence or within his or her knowledge and that the admission of an experts opinion is reviewed for an abuse of discretion
B: holding that a conclusory opinion may be rejected
C: holding that a study showing a statistically insignificant increase in disease incidence following exposure to the alleged causal chemical can properly be rejected by the district court as a foundation for the experts opinion
D: holding that animal studies can be a proper foundation for an experts opinion but that those opinions must be sufficiently supported by the animal studies on which they purport to rely
C.