The correct answer is option 1, Ginger. Ginger is an edible underground stem that is widely used as a spice and herbal remedy. It has a distinctive flavor and aroma and is commonly used in various cuisines and beverages. The stem of the ginger plant, also known as the rhizome, grows underground and is characterized by its knobby appearance. It is harvested, cleaned, and used in both fresh and dried forms. Ginger is known for its many health benefits, including anti-inflammatory and digestive properties. It is often used to soothe upset stomachs and relieve nausea. While sweet potatoes, sugarcane, and radishes are also edible plants, they do not have underground stems like ginger.