The correct option is B Dimorphism
Polymorphism occurs when two or more different phenotypes exist in the same population of a species.
Dimorphism is a phenotypic difference between males and females of the same species. The female Ascaris are longer and wider than the male Ascaris.
Anisogamy is the sexual reproduction involving the union or fusion of two dissimilar gametes.
Regeneration is the process of renewal, restoration, and growth that makes genomes, cells organisms.
Thus, the correct answer is option B.