The author calls Pinker's book 'brilliant, witty and altogether satisfying'. In response to the claim that the book is racist, the author states that Pinkers stresses on the 'fundamental unity of humanity' and 'the universal grammar' of language- the universality of 'the language instinct', in other words, to counter such claims. So, option B is the right choice.

Option C is the exact opposite of the author's position.

According to the passage, Pinker argues that though chimps have the vocal apparatus to speak, their brains, unlike human brains, are unable to produce grammar as chimps do not have the 'language instinct'. The author agrees with Pinker's view, so option A is incorrect.

Again, option D is also incorrect, based on the last paragraph. The author says that while some behavioral psychologists and anthropologists believe human behavior may be changed for the better by improvements in culture and environment, Pinker's position (one that the author agrees with) is that the roots of language are in the genes.