Which of the following are nitrogen-fixing plants? 1. Alfalfa 2. Amaranth 3. Chickpea 4. Clover 5. Purslane (Kulfa) 6. Spinach Select the correct answer using the code given below:

1. The question asks to identify which of the listed plants are nitrogen-fixing. 2. Nitrogen-fixing plants, particularly those in the legume family (Fabaceae), form symbiotic relationships with nitrogen-fixing bacteria (like Rhizobia) in their root nodules, converting atmospheric nitrogen into ammonia. 3. Alfalfa (Medicago sativa) (Item 1) is a well-known legume and is a nitrogen-fixing plant. 4. Amaranth (Amaranthus spp.) (Item 2) belongs to the Amaranthaceae family and is not a nitrogen-fixing plant. 5. Chickpea (Cicer arietinum) (Item 3) is a legume and is a nitrogen-fixing plant. 6. Clover (Trifolium spp.) (Item 4) is a common legume used as forage and cover crop, known for its nitrogen-fixing ability. 7. Purslane (Kulfa) (Portulaca oleracea) (Item 5) belongs to the Portulacaceae family and is not a nitrogen-fixing plant. 8. Spinach (Spinacia oleracea) (Item 6) belongs to the Amaranthaceae family (related to Amaranth) and is not a nitrogen-fixing plant. 9. Therefore, the nitrogen-fixing plants in the list are Alfalfa (1), Chickpea (3), and Clover (4).