it is said that a new robot -------------- by him in a few d

it is said that a new robot ______________ by him in a few days.
A.designed B.has been designed C.will be designed D.will have been designed
为什么选D不选C?
越快越好!
说将要被设计为什么不行啊 句子中并没有将来完成时的标志时间啊