The correct answer is: a) Stone, bone, and wood.
Prehistoric tools discovered in Northeast India were often made from materials like stone, bone, and wood. These materials were readily available and could be easily shaped into tools. Stone tools were used for a variety of purposes, including hunting, gathering, and woodworking. Bone tools were used for a variety of purposes, including sewing, scraping, and carving. Wood tools were used for a variety of purposes, including building, carving, and making weapons.
Iron and copper were not commonly used to make tools in Northeast India until the Iron Age. Plastic and ceramics were not commonly used to make tools until the modern era. Glass and porcelain were not commonly used to make tools in Northeast India at any point in history.