Answer & Explanation
B) Non-Orthologous genes between biologically distinct species can be identified, and it is strong evidence for a related function
Orthologous genes between biologically distinct species (for example, yeast and fruit flies) can be identified, and the high sequence similarity between them is strong evidence for a related function. Given the more complex multicellular biology of flies, the fly gene could have an additional function that is not predictable by the yeast model. In other cases, the occurrence of families of paralogous genes that share common domains can make a precise guess of function of one of these proteins more difficult because all match a model protein to some degree.