单项选择题

A.B超测定胎儿胸径大于胎头双顶径1.3cm
B.B超测定胎儿胸径大于胎头双顶径1.6cm
C.B超测定胎儿胸径大于胎头双顶径1.8cm
D.B超测定胎儿胸围大于头围1.5cm
E.B超测定胎儿胸围大于头围1.8cm