The correct answer is option 1. Calcium ammonium nitrate (CAN) is a popular nitrogen fertilizer because it is a slow supplier of nitrogen. This means that the nitrogen in CAN is released slowly over a period of time, providing a steady and continuous supply of nitrogen to the plants. This slow release of nitrogen is beneficial as it helps to reduce the risk of nitrogen leaching. Nitrogen leaching occurs when excessive nitrogen is applied to the soil and is not absorbed by the plants. The excess nitrogen can then be washed away by rainfall or irrigation, causing water pollution and negatively impacting the environment. By releasing nitrogen slowly, CAN helps to ensure that plants receive a consistent supply of nutrients while minimizing the risk of nitrogen leaching. Additionally, the slow release of nitrogen from CAN can also help to prevent the burning of plant roots, which can occur when nitrogen is applied in excess and in a concentrated form.