"Some men are certainly intelligent, others are certainly notintelligent, but of intermediate men, we should say,‘intelligent’? Yes, I think, so or no, I shouldn't be inclined to call him intelligent." Which of the following most accurately reflects the intention of the writer of the above ?

The author says that apart form a few people who clearly fall in the category of definitely intelligent/definitely not intelligent, there is a definite class of people whom we can label as intelligent and not so at the same time. This makes it ambiguous and the author wonders whether one has the right to call them any of the 2 as per his inclination. This is best reflected in the option C. 
Option A does not cover the author's thought correctly.