Ex. Air freshener.
simple diffusion is the process of a substance (such as air freshener) moving from high concentration to low concentration with little to no energy.
        
             
        
        
        
Answer:
In the gums
Explanation:
Lidocaine is a compound which can be used as a local anaesthetic. This anaesthesia works by blocking the voltage-gated channels which allows the influx of the sodium ions. As the sodium ions do not enter therefore an action potential is not generated in the axons as a result of which no pain is felt in the area.
In the given since the lidocaine is used by the dentist therefore the dentist in order to treat some dental problem must inject the lidocaine in the gums where the sensory receptors of the teeth are present.
Thus, in the gums is the correct answer.
 
        
             
        
        
        
A. Because saturated fatty acids are the ones with no double bonds