Critical Reasoning

A team of Swedish scientists recently concluded a fifteen year study on the relationship between fatty or lean fish consumption and the risk of kidney cancer; the study revealed that those who ate on average more than one serving per week of fatty fish had 44 percent less risk for developing renal cell carcinoma, the most common form of kidney cancer. Though all previous studies on the relationship between fatty fish and the prevalence of kidney cancer have been inconclusive, the Swedish scientists attribute the lower rate of kidney cancer to increased intake of omega 3 fatty acids. Lean fish is rarely rich in omega 3's, and those in the study who ate lean fish had the same risk for developing renal cell carcinoma as those who ate no fish at all.

In the statement above, the two portions in boldface play which of the following roles?
A) The first is an opinion that is supported by the argument; the second is one part of the information uncovered in the study.
B) The first is a fact that goes against the argument that is being presented; the second is one element of a logical argument in support of the scientists' claim.
C)The first presents the quandary the scientists are attempting to solve; the second is the result of that quandary.
D) The first is a claim in support of the argument; the second is a piece of evidence against the argument.
E)The first is an explanation advocated by the argument; the second is a finding used to challenge that explanation.

Source: MGMAT CAT#6
OA : after some discussion

IMO B..

Whats the OA.