It is option D. Please mark as brainliest
Answer:
I believe it is A, but I could be wrong.
Explanation:
I think this, because when it says, "Other, less useful, versions of the genetic code were eliminated gradually throughout the course of evolution", I think it referencing to the fact that all animals and etc, are made up of common codes, and how over time, through evolution, certain codes were eliminated, because creatures were evolving.
When the effects of genes add up to make the phenotype, they are called additive genes.
