What does the grid-like street layout in Harappa and Mohenjodaro strongly suggest about their society?

The cities grew organically without any central oversight.

It indicates a high level of urban planning and organization.

Their primary focus was on building defensive fortifications.

Each neighborhood was built by a different, independent group.

Which technological innovation found in Mohenjodaro demonstrates an advanced concern for public health and sanitation?

Large granaries for storing food

A complex sewer system with clay pipes

The use of standardized weights in trade

The construction of tall city walls

A strong centralized government

A society of independent farmers