Which of the following should NOT be disposed of in a septic system?

The option indicating that non-biodegradable items and chemicals should not be disposed of in a septic system is correct because these materials can cause significant harm to the system. Septic systems rely on natural biological processes to break down waste. Non-biodegradable items, such as plastics, rubber, and certain metals, do not decompose and can lead to blockages in the tank and drainage fields. Additionally, chemicals like solvents and fuels can disrupt the microbial activity necessary for the system to function properly, potentially resulting in system failure and contamination of groundwater. Proper maintenance and appropriate waste disposal are crucial for ensuring that a septic system operates efficiently and remains environmentally safe.