What evidence found by archaeologists suggests organized government planned the indus valley cities?

The streets were perfectly planned and had grid patterns. Their sophisticated and technologically advanced urban culture was very evident from the archaeologists find. They also had their home protected from thieves, noises, and even from odors. This is what suggests the Indus Valley cities had an organized government. 

The answer is d.  the north had organized schools, whereas the south had few organized schools.