In the following question, a short passage is given with one of the lines in the passage missing and represented by a blank. Select the best out of the four answer choices given, to make the passage complete and coherent. 

____________________ The social sciences deal with human beings and the human society along with its various factors. It becomes difficult to objectively monitor and report them because there is always a matter of personal bias that comes in, as we are humans and belong to a society in which we are influenced by the same factors we might be studying. However, the only way to resolve this issue is by accounting for the exceptions in the results that are to be generalized.