The correct answer is: a) Harappa and Mohenjo-daro.
Harappa and Mohenjo-daro are the two most well-known cities of the Harappan Civilization. They were both located in the Indus Valley, in what is now Pakistan. Harappa was founded around 2600 BCE, and Mohenjo-daro was founded around 2650 BCE. Both cities were abandoned around 1900 BCE.
Harappa and Mohenjo-daro were both large cities, with populations of around 25,000 people. They were both well-planned cities, with streets laid out in a grid pattern. The cities were also well-fortified, with walls and moats.
The people of Harappa and Mohenjo-daro were skilled craftsmen. They made pottery, jewelry, and other objects from a variety of materials, including clay, stone, and metal. They also built large public buildings, such as granaries, baths, and temples.
The Harappan Civilization was a complex society with a sophisticated culture. The people of Harappa and Mohenjo-daro were skilled farmers, and they also traded with other cultures in the region. The Harappan Civilization came to an end around 1900 BCE, for reasons that are not fully understood.
The other options are incorrect because they do not represent cities of the Harappan Civilization that were located in Punjab. Rakhigarhi and Kalibangan are located in Haryana, Lothal and Dholavira are located in Gujarat, and Mehrgarh and Kot Diji are located in Balochistan.