Final answer:
The subject described in the question, being 1,141 feet high and 5.8 miles around its base in Australia's Northern Territory, corresponds to Uluru (Ayers Rock), a significant cultural landmark and natural wonder in Australia.
Step-by-step explanation:
The correct answer is A) Uluru (Ayers Rock). Uluru, also known as Ayers Rock, is a gigantic sandstone monolith located in the southern part of the Northern Territory in central Australia. It is one of the most recognisable natural landmarks of Australia and holds great cultural significance for the Anangu, the traditional Aboriginal owners of the land. The dimensions stated in the question, approximately 1,141 feet in height and 5.8 miles around its base, match those of Uluru. This makes Uluru smaller than Mount Augustus, which is considered the largest single rock in the world and is located in Western Australia. The Great Barrier Reef is an underwater structure and the Sydney Opera House doesn't match the physical description provided.