Your source states 
About the Black–White difference in IQ, which at the time was about 15 points, the Neisser et al. (1996) article stated, "There is not much direct evidence on this point, but what there is fails to support a genetic hypothesis." That conclusion stands today: There has been no new direct evidence on the question. (See Rushton & Jensen, 2005a, 2005b, Gottfredson, 2005, and Lynn & Vanhanen, 2002, for the view that the Black–White IQ difference is owing substantially to genetic differences between the races and that indirect evidence having to do with such factors as reaction time and brain size is probative. See Nisbett, 2005, 2009, for the view that the direct evidence indicates that thedifference between the races is entirely due to environmental factors and that the indirect evidence has little value.
Please stop lying. 211.119.109.57  

Then applying the same defintion to C the answer is no. Do you see the problem here? 211.119.109.57     
   
Question C2: Is the "Hereditiarian" position a mainstream view?   
The question is whether it is a widely held mainstream view that the IQ test score gap is likely to be significantly explainable by genetic factors. Note that the question is not whether it is the only mainstream view, nor whether it has been proven to account for the entire gap, but only about whether it is considered a probable explanation by a wide selection of mainstream scholars.   

Yes. 211.119.109.57     
   
Question D2: Is Richard Nisbett considered a mainstream scientist?   
The question is whether Nisbett as a person and a scholar is generally considered to be within the mainstream of the field of Psychology. The question is not whether he is prominent and notable enough to be included, but about whether his views should be given equal weight to mainstream views within the article.   
   
No. Nisbett holds a minority view which has been described as having 'virtually no chance of being true' by a reliable tertiary source. 211.119.109.57