According to paragraph 5, why were the larvae of some populations of the salamander species Ambystoma maculatum once thought to be members of a separate species? A. Because they were shaped differently than other larvae of Ambystoma maculatum. B. Because they were discovered far away from other members of Ambystoma maculatum. C. Because they were sexually mature and could reproduce. D. Because the neotenic form of Ambystoma maculatum looks very different from the neotenic forms of other salamanders.