携带HLA-B27基因的个体与下列哪种自身免疫性疾病密切相关（）

A.类风湿关节炎

B.强直性脊柱炎

C.多发性硬化症

D.桥本甲状腺炎

E.胰岛素依赖型糖尿病

A 9-month-old, well-nourished boy who lives with his extensive extended family tests positive for tuberculosis. Which of the following is a risk factor for tuberculosis in this client

A．Male sex.

B．The infant is in the 95th percentile for height and weight.

C．His mother did not receive prenatal care until the second trimester of her pregnancy.

D．Age.