Three crops that contribute maximum to global food grain production are :

The three crops that contribute the most to global food grain production are wheat, rice, and maize. These crops are staples for a significant portion of the world's population and are grown in vast quantities across different regions. Wheat is a major crop in many parts of the world, including Europe, North America, and Asia. Rice is the primary food crop for more than half of the world's population, especially in Asia. Maize (corn) is widely grown and used not only as a food source but also for animal feed and industrial purposes. Therefore, the correct answer is option (A) wheat, rice and maize. Think of it this way: these three crops are fundamental to the global food system, providing a substantial portion of the world's food energy.