The correct answer is option 1: Sanitary landfilling. Sanitary landfilling involves the disposal of solid waste in low-lying areas and covering it with a layer of earth. This method is used to manage solid waste in a controlled manner to minimize the environmental impact. Sanitary landfilling ensures that waste is contained and does not contaminate the soil, water, or air.

Option 2, Open dumping, refers to the unsystematic and uncontrolled disposal of waste in open areas, which can lead to pollution and health hazards. Option 3, Composting, is a process of decomposing organic waste to produce nutrient-rich compost. Option 4, Incineration, involves the burning of waste at high temperatures, which can help reduce volume but may release harmful pollutants into the air.

Therefore, the most appropriate term for dumping solid waste in low-lying areas with an earth cover is sanitary landfilling.