Explanation: The Indus Valley Civilisation, also known as the Harappan Civilisation, is one of the earliest urban civilisations in the world, dating back to around 3300 BCE to 1300 BCE. This civilisation is considered pre-Aryan, as it predates the arrival of the Indo-Aryan people in the Indian subcontinent, which is estimated to have occurred around 1500 BCE. The term "pre-Aryan" refers to the period before the Indo-Aryan people, who spoke an early form of Sanskrit, entered the Indian subcontinent and influenced the region's culture and language.
Mohenjodaro, located in present-day Pakistan, is one of the most important archaeological sites of the Indus Valley Civilisation. It was discovered in the 1920s and has since provided significant insights into the life and culture of this ancient civilisation. The site is known for its well-planned urban layout, including a grid of streets, a sophisticated drainage system, and large public buildings. Archaeologists have unearthed numerous artefacts at Mohenjodaro, such as seals, pottery, jewellery, and other objects that reflect the advanced nature of the Indus Valley Civilisation.
The other options listed in the question are not associated with the pre-Aryan period. Taxila, located in modern-day Pakistan, is an important site for the Gandhara culture and the Mauryan Empire, which came after the Indus Valley Civilisation. Rajgir, in Bihar, India, is significant in Buddhist and Jain history and is not related to the pre-Aryan period. Indraprastha, a legendary city from the Mahabharata, does not have substantial archaeological evidence linking it to the Indus Valley Civilisation.
In conclusion, Mohenjodaro is the correct answer as it is a key site where relics of the pre-Aryan civilisation, specifically the Indus Valley Civilisation, have been unearthed. The discovery and study of Mohenjodaro have greatly contributed to our understanding of the early urban civilisations in the Indian subcontinent.