Which method is least effective for the body to receive toxins?

Visual perception is least effective for the body to receive toxins because it does not involve any physical or chemical interaction with substances that can lead to toxicity. Visual perception refers to the ability to see and interpret visual stimuli, which does not facilitate the transfer of toxins into the body. The other methods listed—ingestion, inhalation, and absorption—engage different pathways through which toxins can enter the bloodstream and affect physiological functions. Ingestion allows toxins to be absorbed through the digestive system, inhalation facilitates the entry of airborne toxins through the respiratory system, and absorption entails the uptake of substances through the skin or mucous membranes. Each of these methods has a direct route to potentially harmful substances, making them significantly more effective for toxin entry compared to visual perception.