This is the removal of unwanted plants on the farm

The correct answer is: Weeding. "Weeding" refers to the process of removing unwanted plants from a farm or garden to help the desired plants grow better. "Thinning" usually refers to the removal of excess plants to allow the remaining plants to grow stronger and healthier. "Mulching" refers to the practice of covering the soil with a layer of material (such as leaves, straw, or bark) to retain moisture, suppress weed growth, and improve soil quality. "Supplying" does not relate to the removal of unwanted plants on a farm. It could refer to the act of providing necessary resources, such as water or nutrients, to the desired plants.