Here's a verified answer:
B, D, E are all applicable answers. Moctezuma's kidnapping forced Aztecs to beg and pay for years. Spanish disease diminished the Aztec population tremendously, since they have never encountered it and they do not know the medicine for treating it. Trade is the most one of the most important factors in determining a nation/empire's power. If trade was difficult, than of course its economical power would not be high, therefore the decline of the Aztec empire would commence.
