Biologist: A careful study of the behavior of six individual chameleons concluded that lizards such as chameleons bask in the sun not only for warmth but also to regulate their production of vitamin D. Critics of the study -- although correct in observing that its sample size was very small -- are wrong to doubt its results. After all, the study' s author is well regarded professionally and has been doing excellent work for years. The reasoning in the biologist's argument is most vulnerable to criticism on the grounds that the argument ["focuses its attention on the study's author rather than on the study itself", 'takes the behavior of chameleons to be generalizable to lizards as a whole', "fails to demonstrate that the study's critics have relevant expertise", "holds the study's author to a higher standard than it holds the study's critics"]