**Core Concept**
Sewage disposal refers to the process of treating and disposing of wastewater from households, industries, and institutions to prevent contamination of the environment and public health risks. Effective sewage disposal methods involve physical, chemical, and biological processes to remove pollutants and pathogens.

**Why the Correct Answer is Right**
The correct answer is not explicitly provided, but we can infer the correct method of sewage disposal from the options. Common methods of sewage disposal include septic tanks, sewage treatment plants, and landfills. However, without the correct answer, we'll proceed with a general explanation.

**Why Each Wrong Option is Incorrect**
**Option A:** **Septic Tanks** - This is a common method of sewage disposal, especially for households in rural areas. Septic tanks use anaerobic digestion to break down organic matter, and the treated effluent is discharged into a drainage field for further treatment.

**Option B:** **Sewage Treatment Plants** - These are also known as wastewater treatment plants and are used to treat large volumes of sewage. They use physical, chemical, and biological processes to remove pollutants and pathogens from the wastewater.

**Option C:** **Landfills** - While landfills are used for disposing of solid waste, they are not a primary method of sewage disposal. However, some landfills have leachate collection systems to prevent the migration of contaminants into the groundwater.

**Option D:** **Incineration** - This method involves burning waste at high temperatures to reduce its volume and kill pathogens. However, incineration is not a common method of sewage disposal, as it is primarily used for disposing of hazardous waste and medical waste.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that sewage disposal methods should aim to remove at least 85% of suspended solids, 90% of biochemical oxygen demand (BOD), and 95% of total coliform bacteria from the wastewater to prevent environmental pollution and public health risks.

**Correct Answer:** D. Incineration.