The correct answer is option 4: USA. The Indian Air Force has recently acquired the AH-64E (I) - Apache Guardian helicopter, which is manufactured in the United States. The Apache Guardian helicopter is a multi-role attack helicopter that is widely used by several countries, including the United States, as well as other nations around the world. It is known for its advanced technology, firepower, and maneuverability, making it a valuable asset in combat missions. The acquisition of the Apache helicopter by the Indian Air Force is part of the modernization efforts to enhance its operational capabilities and strengthen its defense capabilities. By procuring helicopters such as the Apache Guardian, the Indian Air Force aims to bolster its fleet and be prepared for various security challenges.