Simon has grown accustomed to the sound of his air conditioner, and he doesn't even "hear" it anymore. One day the machine stops working properly, and for 5 minutes it makes a hideous grinding sound. After this subsides, Simon is now very aware of the fan's noise, even though it is the same level that it was before the change occurred. This increased awareness of the air conditioner is an example of ________. 

a) desensitization 

b) sensitization 

c) habituation 

d) sensory dynamics