Who formulated the principle that "ontogeny recapitulates phylogeny"?

Explanation

Option B is correct.The principle that "ontogeny recapitulates phylogeny" was formulated by Ernst Hackel. Hackel was a German biologist who lived from 1834 to 1919. He was a major proponent of Darwin's theory of evolution, and he made a number of important contributions to the field of biology. The principle of ontogeny recapitulating phylogeny states that the development of an individual organism (ontogeny) mirrors the evolutionary history of its species (phylogeny). In other words, as an embryo develops, it goes through stages that resemble the adult forms of its evolutionary ancestors. Hackel based his theory on observations of the development of various animals, including humans. He noted that at certain stages of development, human embryos have features that are similar to those of fish, reptiles, and other animals. The other options are not scientists who formulated the principle of ontogeny recapitulating phylogeny: Karl Ernst von Baer was a German biologist who lived from 1792 to 1876. He is known for his work on the development of embryos. Herbert Spencer was an English philosopher and sociologist who lived from 1820 to 1903. He is known for his work on social Darwinism. Charles Darwin was an English naturalist who lived from 1809 to 1882. He is known for his theory of evolution by natural selection.