Why!I have nothing to do with it._______you want me to say?

A．What it is that

B．How it is that

C．How is it that

D．What is it that

患儿女，4岁。面容特殊，眼距宽，鼻梁平，舌厚肥大，面部臃肿，皮肤粗糙，头发干稀，智力低下，身高80cm，腕部X线检查显示一枚骨化中心。最可能的诊断是（）

A.唐氏综合征

B.先天性甲状腺功能减退症

C.黏多糖病

D.苯丙酮尿症

E.软骨发育不良