The correct answer is option 1: they do not produce seeds. Sugarcane plants are typically propagated by vegetative means because they do not produce viable seeds. This means that they cannot be easily reproduced through traditional methods such as pollination and seed dispersal. Instead, sugarcane plants are propagated by planting stem cuttings or sections of the plant that contain nodes, which are areas where new shoots can develop. By using vegetative propagation methods, farmers can ensure that the genetic quality of the sugarcane plants is maintained. This is important because sugarcane crops with desirable traits, such as high sugar content or disease resistance, can be selected and propagated to produce more plants with these characteristics. Additionally, vegetative propagation can help reduce the incidence of disease, as it allows farmers to avoid introducing pathogens through contaminated seeds.