XAT 2017 Question 19

We must never talk about human nature or human instincts. This implicit moral notion is still very influential, not at all confined to those who use the metaphysic of essence and existence. So I shall sometimes speak of it, not as Existentialist, but as Libertarian"
The notion that human instinct does not exist is still widely popular. It is not only confined to the discussions of metaphysics/philosophy etc, this notion is also popular in the general discourse in masses. Clearly, the author is extending the theory of existentialism to a generic political philosophy such as libertarianism. He is suggesting that this notion is not just accepted or followed by few individuals of metaphysics etc, it can also be easily adopted by libertarians such as himself.
The usage of words implies that, the author is suggesting a commonality of "this notion" in both existentialism and libertarianism. Hence we can say, these 2 philosophies are likely to appear such as this. We can infer the following information from the given sentence.

Hence, option B, C and E are incorrect representation as per the author.
Option D: The author in the next paragraph emphasizes that we need to conduct research on the relation of human and animal behavior. In the above lines(this notion), however, he merely suggests that we shouldn't say that human nature exists .