Why D not C?

Good question. D points out the main criticism: That Pocock's work doesn't fit both the US and England in the 1700s—the author points out that Pocock's ideas are "fertile" when applied to England but "controversial" for the US. The test also seems to be emphasizing the difference between Pocock's work, rather than Pocock himself—so even if Pocock later evolved, his work was the same. The author's main critique doesn't seem to be whether Pocock subscribes to civic humanism, and in fact calls it "fertile" as noted above, but rather critiques the sweeping allocation of the same interpretations and terminology to both sides of the pond.

Thanks Anita!