"Gupta rule came to an end mainly due to attacks from the outside". It is possible to say so, because of the Huns attacks that were taking place in the region. Nevertheless, after the Huns invasions, the Gupta Empiere continued, de-jure, ruling the region, but its power was highly weakened. This new situation made military juntas had much more power on certain regions (being possible to say that option D is quite right). As well as this, there was an internal warfare, with the different regional powers fighting against them. Finally, the lack of power ended in internal chaos against different educational, religious and power institutions and buildings, what could be considered as a popular upraising against the corruption at the highest levels.