Final answer:
Prototype theory reflects the concept that our representation of a category is based on a 'very personal average' that stems from all past encounters with the category. This average forms a prototype that aids in categorizing new instances, with the recognition that this is a deeply individual and evolving process.
Step-by-step explanation:
The correct answer to the question of what is true about prototype theory is d) prototype theory is a very personal average representation of a category. Prototype theory is an approach to cognitive psychology that suggests our mental representations of categories are based on an average of all prior experiences we've had with members of that category, known as a prototype. This prototype helps us to quickly categorize new objects or concepts by evaluating how closely they match our internal prototype.
It is important to note that prototypes are subjective and can differ from person to person because they are influenced by individual's unique experiences and perceptions. Moreover, prototypes are not fixed and can change over time with new experiences and information.