There is only one question plz answer it using the text below. The large subcontinent that is india is borded by a great ancient cilization or Harappan civilization. It is named after Harappa, one of its two important cities, that developed in the Indus river valley. Like other early
civilizations, the river was used for the
irrigation of crops. As farming increased, the population increased, and by about 3,000 B. C.E. neolithic villages were developing into larger cities. The other major city of the Indus Valley was Mohenjo-Daro. Both were large, around three miles in circumference, and had populations of around 40,000. Each had huge hilltop structures called a citadel. Unlike Mesopotamia or Egypt, it is impossible to learn much about the Harappan society for two reasons. First, archeologists cannot get to the earliest Harappan physical remains. Silt deposits buried the lndus valley so high that the level of the land as well as the water table was raised. Thus, the earliest Harappan remains lie below the water table. The earliest remains that archeologists can study begin at about 2500 B. C.E., when the Harappan society was fully developed.
Second, historians cannot decipher Harappan writings. There is no Rosetta Stone for the Harappan written language. Although historians have thousands of clay seals, copper tablets, and other artifacts with Harappan script, they cannot read the ancient writings that allow them to learn details about their society.
Cities were divided into lower dwellings and the higher level citadel, which housed important buildings. The large fortified citadels may indicate the existence of a theocratic and authoritarian society. The citadels were fortified with almost 40 foot walls, which may have served as protection for the cities’ populations in times of attack and as community centers in times of peace. The citadel in Mohenjo-Daro contains the earliest public water tank of the ancient world. The ”Great Bath” measures 39 feet long and 22 feet wide. In the lower dwellings of Mohenjo-Daro, many people lived in one-room tenement structures. At the same time, there were individual houses of two the same time, there were individual houses of two a great ancient and three stories with over 20 - 30 rooms and numerous courtyards. Most of the larger houses had their own wells and built in brick ovens. Almost all of the houses had private bathrooms with showers and toilets that drained into the city sewage systems. The houses and sewage systems were just small features of Harappa and Mohenjo-Daro’s very well planned cities. Each city was laid out in a grid pattern, with rectangular blocks larger than modern city blocks. All houses were built of uniform oven- fired clay bricks. Houses had modern plumbing systems with baths, drains, and water chutes that led into sewers beneath the streets. The reason for this civilization’s demise is unclear. We can only speculate a combination of a few factors such as: climate change left the valley dry with little water; over-planting may have left the cities hungry; and sickness and war may have left the cities too weak to survive. Until researchers are able to decipher Indus script, we may never know what actually occurred.

Question:
1. How can we deduce there were social classes in the Indus civilization?