一对正常夫妇,双方都有耳垂(控制耳垂的基因位于常染色体上),结婚后生了一个色盲、白化且无耳垂的孩子,若这对夫妇再生一儿子,为有耳垂、色觉正常但患白化病的概率多大( )
A:3/8
B:3/16
C:3/32
D:3/64
How kind you are! You always do what you can __________ others.