Final answer:
The phenomenon of failing to notice small vicious dogs due to the preexisting fear and belief that only big dogs are vicious is an example of confirmation bias. This cognitive bias causes individuals to favor and recall information that supports their existing beliefs, while ignoring contradictory evidence.
Step-by-step explanation:
If you are afraid of big dogs and believe they are more vicious, you will likely fail to notice small vicious dogs because of c) confirmation bias. Confirmation bias is the cognitive bias that involves focusing on information that supports your existing beliefs. In this case, if you have a belief that big dogs are more vicious, you are likely to pay more attention to information that supports this belief (such as noticing only the aggressiveness of big dogs) while ignoring evidence that contradicts it (like the aggressiveness of small dogs).
Moreover, confirmation bias can lead to a filtering out of information that does not conform to our preexisting beliefs or paying more attention to events that confirm our beliefs, even if they are not statistically representative. For example, if a person believes that wearing a specific jersey causes their sports team to win, they are likely to remember the wins associated with the jersey and dismiss the losses.