The correct option is
A Genetic recombination, differential reproduction and natural selection
Neo-Darwinism is the "modern synthesis" of Darwinian evolution through natural selection with Mendelian genetics, the latter being a set of primary tenets specifying that evolution involves the transmission of characteristics from parent to child through the mechanism of genetic transfer, rather than the "blending process" of pre-Mendelian evolutionary science. Neo-Darwinism can also designate Charles Darwin's ideas of natural selection separated from his hypothesis of Pangenesis as a Lamarckian source of variation involving blending inheritance. So, neo darwinism explains about genetic recombination, differential reproduction and natural selection.
Therefore, the correct answer is option A.