GWD7-Q1..求解惑

wtc521521

Although producer prices rose at an unexpectedly steep rate in September, analysts said that the increase resulted mostly from temporary 【factors and not necessarily foreshadowing that there would be】a  resurgence of inflation.
B. factors and not necessarily that it foreshadowed
C. factors and did not necessarily foreshadow
D. factors, while not necessarily a foreshadowing of
E. factors , while it did not necessarily foreshadow that there would be
答案 C    
语法笔记中关于foreshadow 和there would be 重复的解释 很容易懂, 但是请问 "省略的did前半个平行结构没有，无法补出，错误" 要怎么理解呢.. 本来选对了..但是对于这个解释..很纠结..

wtc521521

..等待大牛们解答

wtc521521

是对A的解释..抱歉我没说清楚..可是暂不说foreshadow和后面的问题,补上之后的平行关系是怎样的呢...感觉不通顺啊...

听sophie

省略的did前半个平行结构没有，无法补出，错误
这个是对哪个选项的解释？是B么