What is the DNA similarity between identical twins?

Identical twins arise from a single fertilized egg that splits into two embryos, which is why they share the same genetic makeup. This means that their DNA is nearly identical, with only minor differences that might occur due to mutations or environmental factors influencing their epigenetics over time. The genetic similarity allows for identical twins to exhibit very similar physical traits, health conditions, and inherited characteristics, reinforcing the idea that option A is the correct choice. Other options do not accurately represent the fact that the DNA itself is the same between identical twins; they make claims about similarities or differences that do not hold when considering the genetic essence.