食指长于无名指为长食指，反之为短食指，该相对性状由常染色体上一对等位基因控制(T^S表示短食指基因，T^L表示长食指基因)。此等位基因的表达受性激素影响，T^S在男性为显性，T^L在女性为显性。若一对夫妇均为短食指，且丈夫为色盲患者，妻子表现正常。所生孩子既有长食指又有短食指，既有患色盲也有不患色盲。则该夫妇再生一个孩子是长食指且为色盲患者的概率为[ ]

A．1/4

B．1/3

C．1/8

D．3/4

So difficult _______ that no one could ______ a good solution to it. [ ]

A. was the problem; come up with    

B. the problem was; come up with

C. the problem was; put up with      

D. was the problem; put up with