And this genotype cannot exist if we cross these two individuals as shown in the following pundit square. And so what that means is this pedigree cannot describe a disease that is sex link recessive. So it can't be sex link recessive as a result of this inconsistency between the pedigree analysis and the pun and square analysis. So let's continue and let's move on to the sex length dominant and let's show that this cannot be sex length dominant, so it can't be this. So let's put an X over A. What about B?