The correct answer is option 'D', Agra. Here's an explanation:

Introduction:
The Indus Valley Civilization, also known as the Harappan Civilization, existed around 2500 BCE to 1900 BCE in the northwestern regions of the Indian subcontinent. It was one of the world's earliest urban civilizations and had a highly developed urban culture and trade network. Numerous archaeological sites have been excavated in India that provide insights into the Indus Valley Civilization.

Significant Sites of the Indus Valley Civilization:
1. Harappa:
- Harappa is an ancient city located in present-day Pakistan.
- It was one of the major urban centers of the Indus Valley Civilization.
- Excavations at Harappa have revealed well-planned streets, brick houses, public baths, and a sophisticated drainage system.
- Various artifacts like pottery, jewelry, and sculptures have been unearthed at this site.

2. Mohenjo-daro:
- Mohenjo-daro, also located in present-day Pakistan, was another important city of the Indus Valley Civilization.
- It is one of the largest and most well-preserved archaeological sites related to this ancient civilization.
- The excavations at Mohenjo-daro have revealed a complex urban layout, large public buildings, and an advanced water management system.
- Artifacts found at this site include seals, jewelry, toys, and pottery.

3. Lothal:
- Lothal is an excavated site located in present-day Gujarat, India.
- It was a prominent trading center and a major port city of the Indus Valley Civilization.
- The ruins of a dockyard, warehouses, and a marketplace have been discovered at Lothal.
- The site also yielded artifacts such as beads, seals, pottery, and tools.

Agra:
Agra, on the other hand, is not a significant site excavated in India related to the Indus Valley Civilization. Agra is renowned for being the home of the iconic Taj Mahal, which was built during the Mughal period in the 17th century. However, Agra does not have any archaeological remains or excavated sites associated with the Indus Valley Civilization.

Conclusion:
In conclusion, while Harappa, Mohenjo-daro, and Lothal are important archaeological sites related to the Indus Valley Civilization, Agra is not associated with this ancient civilization. Agra is famous for the Taj Mahal, a Mughal-era monument, but it does not have any excavated sites or artifacts from the Indus Valley Civilization.