Choose the word or set of words that, when inserted in the sentence, best fits the meaning of the sentence as a whole.
The success of the Norman Invasion depended on ------- logistical operation: in planning it, William the Conqueror wisely left no detail -------.
A. 
a puzzling . . untarnished
a puzzling . . untarnished B. a realistic . . unsupervised
a realistic . . unsupervised C. an intricate. . overlooked
an intricate. . overlooked D. an erroneous . . ignored
an erroneous . . ignoredE. a flawed . . unattended
a flawed . . unattended 