What is the primary difference between identical twins and fraternal twins?
A) Identical twins share 100% of their genes, while fraternal twins share about 50%
B) Identical twins are always of the same gender, while fraternal twins can be of different genders
C) Identical twins come from different eggs fertilized by different sperm, while fraternal twins come from the same egg
D) Identical twins are the result of genetic mutations, while fraternal twins are not