Women Who Are Heterozygous for a Defective Bruton's Tyrosine Kinase

Women who are heterozygous for a defective Bruton's tyrosine kinase (Btk) gene _____.

A) are more susceptible to infections caused by extracellular pyogenic bacteria
B) have a 50% chance of having a son with X-linked hyper IgM syndrome
C) mount normal B-cell immune responses despite having lowered levels of serum IgG
D) exhibit X-linked agammaglobulinemia
E) have non-random X inactivation in their B cells.