As reported in the journal “Tectonophysi” in March 2015, the world’s largest know asteroid impact zone is located in

The answer is B) Australia. The March 2015 study in Tectonophysics proposed the Warburton Basin in central Australia, which spans parts of South Australia, Western Australia and the Northern Territory, as a very large impact structure. Its estimated extent of roughly 1,000 km is the basis for calling it the largest known impact zone.

• Africa: Africa has notable impact structures such as Vredefort in South Africa, but none matching this scale.
• South America: Impact sites like Vredefort-type structures are not the focus here, and no South American zone matches the reported size.
• North America: Chicxulub (Mexico) is linked to the dinosaur extinction, and Chesapeake Bay and Manson are known craters, but none is the largest.

The concept is impact geology, where the evidence comes from gravity and magnetic anomalies, seismic data and drilling rather than surface craters. It links to the Geography syllabus on the Earth's interior and planetary processes. The Wilkes Land anomaly in Antarctica is often cited as a rival candidate, so keep the source and wording of the report in mind.

Trap: Aspirants often pick Antarctica or Vredefort because they are famous, but the question asks about the specific 2015 report.