What became the true power behind the throne after the period of the “Good Emperors”

ok, but what is your question? as soon as you tell me i will answer your question : )

answer; ///i believe that the correct answer is (a) the great depression

worldwide, 780 million people do not have access to an improved water source. an estimated 2.5 billion people lack access to improved sanitation (more than 35% of the world's population)

they spoke the dravidian language. hope this , correct me if im wrong