EXPLANATION FROM Fox LSAT

No, this is stupid. This logic is like saying, “Fifty-five percent of the class is female, and fifty-five percent of the class is under the age of 30, therefore 110 percent of the class is female and under the age of thirty.” That’s obviously absurd, and what it’s doing is ignoring the overlap—you’re counting quite a few under-thirty females twice in that analysis. Same thing here, with the bikes. How do we know that failure to obey traffic regulations and inadequate safety equipment aren’t both factors in some of the accidents? (Example: The drunken idiot on a bike with no lights, and no reflective gear, who runs a stop sign and gets squished by a UC Davis Unitrans bus.)

We are asked to identify a flaw. My prediction is, “Ignores the potential overlap.”

A) Not what I’m looking for.

B) The argument doesn’t do this, and it’s not what I’m looking for.

C) This answer basically means, “Ignores the possible overlap.” Great answer.

D) Nah, you aren’t required to provide a source for every premise you offer on the LSAT. There’s just not room for all the citations—every argument would be four pages long if they had to go into all that detail.

E) Huh? Severity of injuries is just not at issue here.

Our answer is C, because it’s the worst flaw present in the columnist’s argument.
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Columnist: The failure of bicyclists to obey traffic regulations is a causal factor in more than one quarter of the traffic accidents involving bicycles. Since inadequate bicycle safety equipment is also a factor in more than a quarter of such accidents, bicyclists are at least partially responsible for more than half of the traffic accidents involving bicycles.

The columnist’s reasoning is flawed in that it

The highlighted text is the conclusion(an inference rather). It is based on the two factors elaborated earlier, which seems to not overlap each other as projected.

(A) presumes, without providing justification, that motorists are a factor in less than half of the traffic accidents involving bicycles - WRONG. It may be true but we aren't concerned about motorists as a factor.
(B) improperly infers the presence of a causal connection on the basis of a correlation - WRONG. A trap answer as it uses similar/same words as used in passage. More so for it says that the passage draws an inference which it actually does and for this reason, at first look, it looks a strong contender relative to other choices. Also, what correlation ?? There's none.
(C) fails to consider the possibility that more than one factor may contribute to a given accident - CORRECT. In a way it says that factors can overlap, thus the inference may not be right.
(D) fails to provide the source of the figures it cites - WRONG. We need not to have a source as it is not discussed nor that it would have had any significance.
(E) fails to consider that the severity of injuries to bicyclists from traffic accidents can vary widely - WRONG. Severity like source of figures is irrelevant.

Answer C.
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