Colin Mackenzie was a British army officer and a pioneering surveyor who made significant contributions to the study and documentation of the Indian subcontinent during the early 19th century. He extensively surveyed various regions in southern India, including Hampi, and produced detailed reports and drawings of the region's historical and archaeological remains. His work was crucial in bringing to light the ruins at Hampi and providing valuable insights into the history and culture of the Vijayanagara Empire. Mackenzie's contributions were instrumental in the later understanding, preservation, and study of the site, solidifying his place in the history of Indian archaeology and historical research.

So, the correct option is [4].