I'm studying the incidence of multiple sclerosis, and I find a small, sparsely populated, isolated island in which nobody has multiple sclerosis. I checked on every person on that island. I conclude that there is something about living on that island that is protective against getting multiple sclerosis. The mistake I have made in my reasoning involves... a. My sample wasn't appropriately stratified for the people of the island. b. my sample wasn't representative of the people on the island c. neglecting the law of large numbers. d. None of the other answers