Lets say that the genotypes are:
Male affected:XbY
Male unaffected: XaY
Female affected: XbXb
Female carrier: XaXb
Female unaffected:XaXa
P: XbY x XaXa
F1: XaXb XaXb XaY XaY The middle square is female carrier.
P:XbY x XaXb
F1: XaXb XbXb XaY XbY The left square is affected female.
P:XaY x XbXb
F1: XaXb XaXb XbY XbY The right square is affected male.
The surface tension of a liquid results from an imbalance of intermolecular attractive forces, the cohesive forces between molecules: A molecule in the bulk liquid experiences cohesive forces with other molecules in all directions. A molecule at the surface of a liquid experiences only net inward cohesive forces.
Answer:
B) a nonsense mutation; this is because a nonsense mutation results in the change of a regular amino acid codon into a stop codon, which ceases translation. This fits with the problem's description of the protein that causes the symptoms as too short, as translation is the process by which proteins/polypeptides are created. A missense mutation would not be the answer because it still codes for an amino acid, which would not shorten the protein. A duplication of the gene would probably just lengthen the protein or not affect its length at all.
Theres your answer look at the photo