Recently the Chemicaticus Company opened a processing plant near a Florida game preserve. Three months after a major toxic leak from the plant, much of the nearby plant life died and people saw fewer and fewer birds and insects. Bill is an environmentalist and Joe is a co-worker of his.

Bill: "That leak from the plant is killing the local flora and fauna. Chemicaticus must be stopped."
Joe: "What is 'flora' and 'fauna'?"
Bill: "Plants and animals."
Joe: "Oh. So you think the leak killed the plants and animals?"
Bill: "Yes I do. After all, the leak was toxic, most of it ended up in the area that is now depopulated, and the plants and wildlife were doing just fine until after the leak. It would be an odd coincidence if the plants just started dying on their own and it had nothing to do with being soaked in industrial waste."
Joe: " Yeah? Well, the company officials say that the plants were dying because the birds and insects had left the area and that the spill had nothing to do with it."
Bill: "And you believe them?"
Joe: "Sure, the bird and bugs just left and this made the plants start dying. Sometimes bugs and birds just go away, you know. I also remember seeing one of those nature shows about how plants need bugs and birds to live. So it is just one of those things."Post HocBiased SampleConfusing Cause and EffectIgnoring a Common CausePost Hoc: This is a wrong answer. While causal reasoning is taking place, neither Bill nor Joe are asserting that one event caused another simply because one occurred prior to the other.Biased Sample: This is a wrong answer. There are no samples mentioned and no generalization is being made by either Bill or Joe.Confusing Cause and Effect: This is a wrong answer. While causal reasoning is taking place, neither person appears to be mistaking a cause for an effect or vice versa.Ignoring a Common Cause: This is the right answer. Since toxic chemicals will harm plants, insects and birds and a leak occurred in the area in question it is reasonable to believe that the actual cause of both the dead plants and the absence of birds and insects was the leak. This is further supported by the fact that an absence of bird and insects is unlikely to cause the plants to rapidly die.There is no mention of samples.4