求助：
一道GMAT语法题目：official guide 第656页第21题。
原题为：Defense attorneys have occasionally argued that their clients’misconduct stemmed from a reaction to something ingested, but in attributing criminal or delinquent behavior to some food allergy, the perpetrators are in effect told that they are not responsible for their actions.
(A)in attributing criminal or delinquent behavior to some food allergy
(B)if criminal of delinquent behavior is attributed to an allergy to some food
(C)in attributing behavior that is criminal or delinquent to an allergy to some food
(D)if some food allergy is attributed as the cause of criminal or delinquent behavior
(E)in attributing a food allergy as the cause of criminal of delinquent behavior
为什么答案选B，if 在句子里是什么意思，作什么成分？这整句话又是什么意思？先行谢过。fficeffice" />